84 results on '"R. Bollini"'
Search Results
52. Novel lectin-related proteins are major components in lima bean (Phaseolus lunatus L.) seeds.
- Author
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Sparvoli F, Gallo A, Marinelli D, Santucci A, and Bollini R
- Subjects
- Amino Acid Sequence, Cloning, Molecular, Cross Reactions immunology, Evolution, Molecular, Molecular Sequence Data, Peptide Fragments, Plant Lectins, Plant Proteins analysis, Plant Proteins chemistry, Protein Conformation, Seeds chemistry, Sequence Alignment, Sequence Analysis, DNA, Sequence Homology, Nucleic Acid, Trypsin Inhibitors, alpha-Amylases antagonists & inhibitors, Fabaceae chemistry, Lectins chemistry, Plants, Medicinal
- Abstract
The only component of the lectin-related protein family so far reported in Lima bean (Phaseolus lunatus L.) seeds is the minor seed lectin (LBL). In the morphotype Big Lima, we have isolated and characterised two abundant lectin-related seed proteins and the corresponding cDNA clones. The clones show 93.7% nucleotide identity and encode an arcelin-like (ARL) and an alpha-amylase inhibitor-like (AIL) protein. Not considering the signal peptides, ARL and AIL polypeptides contain 239 and 233 amino acids, respectively. Each polypeptide is present in the mature protein as two glycoforms. ARL subunits (43 and 46 kDa) make up oligomers of about 125 to 130 kDa whereas AIL subunits (40 and 42 kDa) oligomerise in dimers of about 88 to 100 kDa. cDNA clones encoding two isoforms of the less abundant Lima bean lectin were also isolated. In common bean (P. vulgaris) the lectin locus encodes the lectin and the lectin-related proteins alpha-amylase inhibitor and arcelin, all plant defence proteins. Our data indicate extensive evolution of the locus also in Lima bean. more...
- Published
- 1998
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53. Protein quality control along the route to the plant vacuole.
- Author
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Pedrazzini E, Giovinazzo G, Bielli A, de Virgilio M, Frigerio L, Pesca M, Faoro F, Bollini R, Ceriotti A, and Vitale A
- Subjects
- Biological Transport, Cell Compartmentation, Endoplasmic Reticulum metabolism, Golgi Apparatus metabolism, Hydrolysis, Molecular Chaperones metabolism, Plant Proteins chemistry, Plants, Genetically Modified, Protein Processing, Post-Translational, Plant Proteins metabolism, Plants, Toxic, Nicotiana metabolism, Vacuoles metabolism
- Abstract
To acquire information on the relationships between structural maturation of proteins in the endoplasmic reticulum (ER) and their transport along the secretory pathway, we have analyzed the destiny of an assembly-defective form of the trimeric vacuolar storage glycoprotein phaseolin. In leaves of transgenic tobacco, where assembly-competent phaseolin is correctly targeted to the vacuole, defective phaseolin remains located in the ER or a closely related compartment where it represents a major ligand of the chaperone BiP. Defective phaseolin maintained susceptibility to endoglycosidase H and was slowly degraded by a process that is not inhibited by heat shock or brefeldin A, indicating that degradation does not involve transport along the secretory pathway. These results provide evidence for the presence of a quality control mechanism in the ER of plant cells that avoids intracellular trafficking of severely defective proteins and eventually leads to their degradation. more...
- Published
- 1997
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54. Bean (Phaseolus vulgaris L.) protoplasts as a model system to study the expression and stability of recombinant seed proteins.
- Author
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Giovinazzo G, Greco V, Vitale A, and Bollini R
- Abstract
A suitable protocol for the transient expression of seed protein genes in protoplasts derived from cell suspension cultures of common bean has been established. Preliminary analyses of cultures to verify the synthesis of phaseolin - actively accumulated by the starting tissue, the developing cotyledon - showed that the protein was no longer synthesised after 5 days of culture. Transient expression of a phaseolin sequence, driven by a constitutive promoter, resulted in the accumulation of the correctly glycosylated and assembled protein. This system, when compared to tobacco protoplasts, largely avoids phaseolin fragmentation and the presence of contaminant polypeptides in the immunoprecipitates. Therefore, bean protoplasts are a good system to study the expression of wild-type as well as in-vitro-modified bean seed proteins. more...
- Published
- 1997
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55. The Rate of Phaseolin Assembly Is Controlled by the Glucosylation State of Its N-Linked Oligosaccharide Chains.
- Author
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Lupattelli F, Pedrazzini E, Bollini R, Vitale A, and Ceriotti A
- Abstract
Many of the proteins that are translocated into the endoplasmic reticulum are glycosylated with the addition of a 14-saccharide core unit (Glc3Man9GlcNAc2) to specific asparagine residues of the nascent polypeptide. Glucose residues are then removed by endoplasmic reticulum-located glucosidases, with diglucosylated and monoglucosylated intermediates being formed. In this study, we used a cell-free system constituted of wheat germ extract and bean microsomes to examine the role of glucose trimming in the structural maturation of phaseolin, a trimeric glycoprotein that accumulates in the protein storage vacuoles of bean seeds. Removal of glucose residues from the N-linked chains of phaseolin was blocked by the glucosidase inhibitors castanospermine and N-methyldeoxynojirimycin. If glucose trimming was not allowed to occur, the assembly of phaseolin was accelerated. Conversely, polypeptides bearing partially trimmed glycans were unable to form trimers. The effect of castanospermine on the rate of assembly was much more pronounced for phaseolin polypeptides that have two glycans but was also evident when a single glycan chain was present, indicating that glycan clustering can modulate the effect of glucose trimming on the rate of trimer formation. Therefore, the position of glycan chains and their accessibility to the action of glucosidases can be fundamental elements in the control of the structural maturation of plant glycoproteins. more...
- Published
- 1997
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56. [Postischemic dysfunction and persistent ischemia in the early postinfarction period. Evaluation by echo-dobutamine-atropine test].
- Author
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Rosselli P, Garfagnini A, Bianchi F, Zigliara A, Gostoli E, Bollini R, De Marchi E, and Boggiano P
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- Adult, Aged, Coronary Angiography, Data Interpretation, Statistical, Electrocardiography, Follow-Up Studies, Humans, Middle Aged, Myocardial Infarction complications, Myocardial Ischemia diagnostic imaging, Risk Factors, Time Factors, Atropine, Dobutamine, Echocardiography, Myocardial Ischemia diagnosis
- Abstract
Aim: To study post-ischemic dysfunction and persistent ischemia in early post-infarction, by means of Echo-dobutamine-Atropine stress test (ECHO-DOB). Methods. We studied 138 patients (pts) aged <; or = 75 yrs (mean 59.2 +/- 9.8) at their first uncomplicated myocardial infarction (AMI), treated with systemic thrombolysis. All pts underwent the test within 2 weeks since the onset of the attack and they were reevaluated in follow-up 3 months later. Under Echo and ECG monitoring, ECHO-DOB was performed according to EDICS protocol. Low doses was infused (5-10 mcg/Kg/min every 3') to assess the viability and high doses (20 > or = 40 mg/Kg/min + Atropine) to assess a possible persistent ischemia. The Wall Motion Score Index (WMSI) was used for the semiquantitative analysis of kinesis in a model of left ventricle divided into 16 segments. coronary angiography was performed within 30 days from the AMI, in 82.3% of pts. Results. Low dose of Dobutamine (DOB) induced in 92/136 (67.6%) pts an improvement in the contractile dysfunction in the region of necrosis; in 31.5% (29/92) it remained until the end of the test, suggesting the presence of viable myocardium, In absence of myocardium "at risk". High doses DOB induced worsening of contractile dysfunction in 64 pts (47%); in 40 (62.5%) viability had been previously detected (viable but ischemic myocardium); In 30 (75%) it was homozone or adjacent (viable but ischemic myocardium in the region of the coronary artery or in the tributary vessels correlated to the necrosis). In 24/64 (37.5%) pts the absence of modification of WMSI (no improvement and no worsening), suggested the presence of necrotic tissue in the tributary region of the vessel of necrosis. The significant improvement in kinesis revealed in 92 pts, by the follow-up control was confirmed in 64 (p < 0.001) (69.5%). Forty-four pts without hyperkinesia showed no significant improvement compared with the base line (stunned or hibernating myocardium). The sensitivity of low doses for viable myocardium (gold standard follow-up) was 69%; specificity was 77%. The sensitivity of high doses for ischemia (gold standard coronary arteriography) was 78%; specificity was 100%. No major side effects during the Dobutamine Atropine test were observed., Conclusions: The ECHO-DOB test in the post-infarction period allow the assessment of the functional significance of what is the objectified by coronary angiography and identifies pts at risk of more serious events. An integration of the test with the angiographic data can direct towards more suitable therapeutical or surgical choices. more...
- Published
- 1996
57. In vivo endoproteolytically cleaved phaseolin is stable and accumulates in developing Phaseolus lunatus L. seeds.
- Author
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Sparvoli F, Daminati MG, Lioi L, and Bollini R
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- Amino Acid Sequence, Blotting, Southern, Blotting, Western, Chromatography, Ion Exchange, Cross Reactions immunology, Endoplasmic Reticulum metabolism, Fabaceae genetics, Fabaceae metabolism, Gene Dosage, Genes, Plant, Glycoproteins chemistry, Glycoproteins metabolism, Glycosylation, Molecular Sequence Data, Molecular Weight, Peptides chemistry, Peptides metabolism, Plant Proteins genetics, Plant Proteins metabolism, Protein Conformation, Protein Processing, Post-Translational, Seeds metabolism, Sequence Homology, Amino Acid, Fabaceae chemistry, Plant Proteins chemistry, Plants, Medicinal, Seeds chemistry
- Abstract
Phaseolin is the most abundant storage protein of bean seeds. To modify its amino-acidic composition by protein engineering, for the improvement of its nutritional value, regions which could be modified without detrimental effects on structural features of the protein must be identified. Data presented here, on the characterisation of the major storage protein of lima bean (Phaseolus lunatus L.) seeds, a phaseolin-like glycoprotein, provide good indications on one of such region. Phaseolus lunatus phaseolin consists of four major oligomers containing two subunit classes. Polypeptides of one class show a molecular mass ranging from 38.5 kDa to 32 kDa, while the molecular mass of polypeptides belonging to the other class ranges from 27 kDa to 21 kDa. The subunits originate from the cleavage of precursor forms, with molecular masses of 58 kDa and 54 kDa, which are still present - in residual amounts - in the nature protein. Comparison of their N-terminal sequences with those of the subunits demonstrate that cleavage occurs in a region of the molecule that instead remains uncleaved in phaseolins of the other species. Since this region can accommodate such a drastic modification, we suggest it could be a good candidate for in vitro manipulation. more...
- Published
- 1996
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58. [The re-evaluation of the vasodepressive component in the carotid sinus syndrome].
- Author
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Gaggioli G, Brignole M, Menozzi C, Oddone D, Gianfranchi L, Bollini R, Bottoni N, and Lolli G
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- Aged, Aged, 80 and over, Analysis of Variance, Blood Pressure, Female, Humans, Male, Massage, Middle Aged, Photoplethysmography methods, Photoplethysmography statistics & numerical data, Syncope physiopathology, Syndrome, Baroreflex, Carotid Artery Diseases physiopathology, Carotid Sinus physiopathology
- Abstract
Background: The evaluation of the vasodepressor (VD) reflex of the carotid sinus syndrome is usually inaccurate, due to the difficulty in blood pressure measurement., Aim: To study the VD reflex with a beat-to-beat not invasive technique., Methods: We investigated 68 patients (49 males, 19 females; mean age 70 +/- 11 years) affected by carotid sinus syndrome: cardioinhibitory (CI) form was present in 47 patients, mixed (M) form in 10 patients and VD form in 11 patients. The control group consisted of 9 patients (6 male, mean age 71 +/- 8 years) affected by third degree atrioventricular block who had received the implant of a permanent pacemaker and were pacemaker-dependent with a prolonged asystole at time of temporary inhibition of the pacemaker itself. The study of the VD reflex was performed in the supine position; beat-to-beat arterial systolic pressure was monitored by a photoplethysmographic method using a finger cuff (Finapres technique)., Results: In all the patients the carotid sinus massage caused a marked fall in systolic blood pressure which was greatest at the end of the massage: from 143 +/- 25 mm Hg to 74 +/- 20 mm Hg in the patients with CI form, from 144 +/- 14 mm Hg to 76 +/- 18 mm Hg in those with M form and from 125 +/- 26 mm Hg to 65 +/- 13 mm Hg in those with VD form. A decrease in systolic blood pressure > or = 50 mm Hg occurred in 84% of cases. Afterwards, the patients with CI form had a progressive increase of systolic blood pressure that reached the initial value after a mean of 27 seconds. In the patients with VD form systolic blood pressure was significantly (p < or = 0.5) lower than that observed in all the other groups, beginning from the third second after the end of the massage; mean systolic blood pressure value remained significantly lower than the initial value for more than 27 seconds. The patients with M form showed an intermediate pattern. Also control group patients showed a fall in systolic blood pressure immediately after pacemaker inhibition (from 152 +/- 29 mm Hg to 87 +/- 25 mm Hg) that was of similar extent than that observed in carotid sinus syndrome patients, but pressure returned to initial value within 9 seconds., Conclusions: An important VD reflex is present in most patients with carotid sinus syndrome. It lasts more than the CI reflex and it persists for several seconds after the end of the massage. The initial fall of systolic blood pressure is of similar extent in all the forms of carotid sinus syndrome, but the patients with the VD form are characterized by a longer duration and greater entity of the decrease. These results point out the importance of the VD reflex in patients with the carotid sinus syndrome. more...
- Published
- 1995
59. A new pacemaker for paroxysmal atrial fibrillation treated with radiofrequency ablation of the AV junction.
- Author
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Brignole M, Gianfranchi L, Menozzi C, Bottoni N, Bollini R, Lolli G, Oddone D, and Gaggioli G
- Subjects
- Aged, Atrial Fibrillation physiopathology, Atrial Fibrillation surgery, Combined Modality Therapy, Electrocardiography, Exercise Test, Female, Humans, Male, Atrial Fibrillation therapy, Atrioventricular Node surgery, Catheter Ablation, Pacemaker, Artificial adverse effects
- Abstract
Atrial fibrillation is a relative contraindication to atrial synchronous pacing because of the risk of the tracking of rapid atrial rhythms by the pacemaker. In this study, we describe the clinical results of an AV synchronous rate responsive pacemaker with an original algorithm, which is able to sense pathological increments in atrial rate and automatically to switch into a non-AV synchronous mode of pacing. This pacemaker was implanted in 12 patients who had undergone radiofrequency ablation of the AV junction in order to cure severely symptomatic, drug refractory, paroxysmal atrial fibrillation. In an acute, intrapatient comparison between the standard AV synchronous mode and the automatic switching mode, ventricular tracking of atrial fibrillation occurred in 35% and 4% of total beats at rest and in 24% and 2% of total beats during exercise, respectively (P < 0.001). During 5 +/- 4 months of follow-up, no further tachyarrhythmia related symptoms occurred. In conclusion, the standard DDDR mode is unable to eliminate ventricular tracking of atrial fibrillation, thus undermining the efficacy of AV junction ablation therapy. The automatic switching mode eliminates this adverse effect of dual chamber pacing. more...
- Published
- 1994
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60. Influence of atrioventricular junction radiofrequency ablation in patients with chronic atrial fibrillation and flutter on quality of life and cardiac performance.
- Author
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Brignole M, Gianfranchi L, Menozzi C, Bottoni N, Bollini R, Lolli G, Oddone D, and Gaggioli G
- Subjects
- Activities of Daily Living, Aged, Atrial Fibrillation psychology, Chronic Disease, Dyspnea diagnosis, Exercise Test, Female, Humans, Male, Middle Aged, Pacemaker, Artificial, Prospective Studies, Single-Blind Method, Atrial Fibrillation therapy, Catheter Ablation, Quality of Life
- Abstract
The purpose of this study was to evaluate the effects of atrioventricular junction radiofrequency ablation on the quality of life, exercise performance, and echocardiographic parameters in 23 patients with chronic, severely symptomatic, drug-refractory atrial fibrillation or flutter. Initially, patients were randomized to receive ablation plus pacemaker therapy (n = 12) or pacemaker therapy alone (n = 11). After 15 days, palpitations decreased by 92% and 37% (p = 0.004), rest dyspnea by 79% and 40% (p = NS), effort dyspnea by 65% and 30% (p = 0.03), exercise intolerance by 54% and 17% (p = 0.005), and asthenia by 67% and 31% (p = 0.02) in the 2 groups, respectively. At the end of this short-term study, control patients also underwent ablation therapy, and a 3-month intrapatient follow-up study was performed in 22 patients. New York Heart Association functional class > or = 3 was present in 14 patients (64%) before, but in only 3 patients (14%) after ablation therapy (p = 0.002); specific activity scale functional class > or = 3 was present in 9 patients (41%) before, but in only 5 (23%) after ablation therapy (p = NS). Exercise duration during standardized stress testing increased by a mean of 63 +/- 93 seconds (15% increase) (p = 0.001). In the 9 patients with depressed left ventricular systolic function, echocardiographic fractional shortening increased by 34% (from 23 +/- 5% to 31 +/- 9%) (p = 0.003). In the remaining 13 patients with normal systolic function, fractional shortening decreased by 10% (from 40 +/- 5% to 36 +/- 6%) (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) more...
- Published
- 1994
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61. [Identification of ischemic and/or viable myocardium in early post-infarction period using echocardiographic imaging technique. Comparison of 2 tests: echo-dipyridamole and echo-dobutamine].
- Author
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Rosselli P, Garfagnini A, Bianchi F, Bollini R, Zigliara A, De Marchi E, and Boggiano P
- Subjects
- Adult, Aged, Coronary Angiography, Echocardiography, Exercise Test, Female, Humans, Male, Middle Aged, Myocardial Contraction, Myocardial Infarction drug therapy, Thrombolytic Therapy, Dipyridamole, Dobutamine, Myocardial Infarction diagnostic imaging
- Abstract
Aim of the Study: To compare two stress tests: Dipyridamole-echocardiography (ECHO-DIP) and Dobutamine-echocardiography (ECHO-DOB) with angiographic data (still "gold standard") in early postinfarction period in order to identify ischemic and/or viable myocardium (considering the echocardiographic follow-up as "gold standard")., Methods: 40 consecutive patients (pts), mean age 56, at their first uncomplicated acute myocardial infarction (AMI) treated with thrombolytic agents were studied. All underwent coronary angiography., Results: The ECHO-DIP test resulted positive in 17 pts for transient regional asynergy (homozone 13/17; heterozonal positivity 4/17). The mean basal Wall Motion Score Index (WMSI) was 0.46 +/- 0.30 and at asynergy was 0.58 +/- 0.33 (p < 0.001). The ECHO-DOB test resulted positive in 20 pts; mean basal WMSI was 0.42 +/- 0.31 and at asynergy 0.55 +/- 0.35 (p < 0.001). Both tests were positive in 14 pts; the site of regional asynergy was the same in each test. During ECHO-DOB hypercinesia appeared in 27/39 pts (WMSI form basal 0.42 +/- 0.31 to 0.22 +/- 0.21 p < 0.001). Recovery of contractile function seems to identify viable myocardium: viable tissue shows early functional recovery during ECHO-DOB infusion. In 14 pts it remained until the end of the test, and in 12 it was transient, denoting the presence of myocardium "at risk". Remote (3- or 6-month) clinical and echocardiographic follow-up were carried out in all pts (25 undergoing medical therapy and 15 after PTCA or coronary bypass). In 26 pts with hyperkinesia at ECHO-DOB, basal echocardiogram revealed improvement of WMSI from 0.42 +/- 0.31 to 0.32 +/- 0.29 (p < 0.001)., Conclusions: "Passive" ECHO-stress tests in the early postinfarction period are easy to perform and free of major risks, they allow pts at risk due to residual ischemia to be revealed with a high degree of specificity and sensitivity. The improvement of kinesis during inotropic stimulus of Dobutamine suggests stunned or hibernating myocardium. more...
- Published
- 1994
62. Pigment production from in vitro cultures of Alkanna tinctoria Tausch.
- Author
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Mita G, Gerardi C, Miceli A, Bollini R, and De Leo P
- Abstract
An in vitro culture of Alkanna tinctoria Tausch cells was set up in order to investigate the possibility of producing alkannin, a red naphthoquinone naturally present in the root bark of this plant. Furthermore, an in vitro culture of callusderived roots was established and the production of alkannin evaluated. In the different experimental conditions investigated, differences in the production of alkannin derivatives as well as in the type of pigments produced, were observed. The potential use of this technology is discussed. more...
- Published
- 1994
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63. Bean homologs of the mammalian glucose-regulated proteins: induction by tunicamycin and interaction with newly synthesized seed storage proteins in the endoplasmic reticulum.
- Author
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D'Amico L, Valsasina B, Daminati MG, Fabbrini MS, Nitti G, Bollini R, Ceriotti A, and Vitale A
- Subjects
- Amino Acid Sequence, Animals, Carrier Proteins isolation & purification, Carrier Proteins metabolism, Endoplasmic Reticulum metabolism, Endoplasmic Reticulum Chaperone BiP, Fabaceae drug effects, Mammals, Mice, Molecular Sequence Data, Organelles metabolism, Plant Proteins isolation & purification, Plant Proteins metabolism, Sequence Homology, Amino Acid, Carrier Proteins biosynthesis, Fabaceae metabolism, Heat-Shock Proteins, Molecular Chaperones, Plant Proteins biosynthesis, Plants, Medicinal, Seeds metabolism, Tunicamycin pharmacology
- Abstract
Treatment of developing bean cotyledons with the inhibitor of N-glycosylation tunicamycin enhanced the synthesis of at least two polypeptides with molecular mass 78 kDa and 97 kDa. Pulse-chase experiments and subcellular fractionation indicated that these are endoplasmic reticulum (ER) residents. The 78 kDa protein is a major component of the ER protein fraction and, by N-terminal sequencing, was identified as a bean homolog of the mammalian 78 kDa glucose-regulated protein (GRP78). This is a molecular chaperone that is probably involved in the folding and oligomerization of several animal and yeast proteins in the ER. When newly synthesized storage glycoproteins phaseolin, phytohemagglutinin or alpha-amylase inhibitor were immunoprecipitated from an ER preparation of tunicamycin-treated tissue, the GRP78 homolog was always co-precipitated. Bound GRP78 homolog could be released by ATP treatment. These results suggest that, at least when glycosylation is inhibited, this protein plays a role in the early stages of the synthesis of vacuolar storage proteins. more...
- Published
- 1992
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64. Expression of the wild-type and mutated vacuolar storage protein phaseolin in Xenopus oocytes reveals relationships between assembly and intracellular transport.
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Ceriotti A, Pedrazzini E, Fabbrini MS, Zoppe M, Bollini R, and Vitale A
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- Animals, Cells, Cultured, Cloning, Molecular, Female, Glycosylation, Kinetics, Macromolecular Substances, Plant Proteins isolation & purification, Protein Conformation, Protein Processing, Post-Translational, RNA administration & dosage, RNA genetics, RNA isolation & purification, Recombinant Proteins biosynthesis, Recombinant Proteins isolation & purification, Xenopus laevis, Fabaceae genetics, Oocytes physiology, Plant Proteins metabolism, Plants, Medicinal
- Abstract
The role played by subunit assembly in the intracellular transport of the bean storage protein phaseolin, a soluble trimeric glycoprotein, was investigated using Xenopus oocytes injected with RNA. We show that phaseolin assembly is dependent upon the level of synthesis of the protein and is required for intracellular transport out of the endoplasmic reticulum. We also show that a fraction of the assembled phaseolin is permanently retained in a post-endoplasmic reticulum compartment. Deletion of the C-terminal alpha-helical domain fully prevents in vivo assembly but not endoplasmic reticulum retention. This indicates that this domain is necessary for trimerization but not for interactions of unassembled subunits with endoplasmic reticulum components. The truncated phaseolin has high in vivo stability. The potential implications of these findings on the possibility to improve the nutritional value of phaseolin through genetic engineering are discussed. more...
- Published
- 1991
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65. Intrapatient comparison between chronic VVIR and DDD pacing in patients affected by high degree AV block without heart failure.
- Author
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Menozzi C, Brignole M, Moracchini PV, Lolli G, Bacchi M, Tesorieri MC, Tosoni GD, and Bollini R
- Subjects
- Aged, Atrial Function physiology, Atrial Natriuretic Factor blood, Cardiac Output, Double-Blind Method, Echocardiography, Doppler, Exercise Test, Female, Heart Block blood, Heart Block physiopathology, Humans, Male, Prospective Studies, Cardiac Pacing, Artificial methods, Heart Block therapy, Heart Failure physiopathology
- Abstract
In patients affected by high degree AV block without preexisting congestive heart failure there is no definite demonstration that DDD pacing gives real clinical advantages in respect to VVIR pacing. We performed an intrapatient, long-term study between the two pacing modes in 14 high degree AV block patients, using the Medtronic Synergyst 7027 dual chamber pacemaker, who could be programmed alternatively in DDD or VVIR mode. After a 4-week run-in period following the pacemaker implant, patients completed a randomized, double-blind, cross-over study to compare the effect of 6-week period VVIR and DDD pacing on symptoms and cardiovascular parameters. A semiquantitative score scale was used to quantify the symptoms of general well-being, palpitations, dizziness, pulsating sensation in the neck or abdomen, shortness of breath at rest and during effort, chest pain, and NYHA classification. The sum of symptom scores was 10.4 +/- 6.7 in VVIR period and 4.6 +/- 2.7 in DDD period (P less than 0.001); five patients (36%) crossed over early from VVIR to DDD because of intolerable symptoms; overall, eight patients preferred the DDD mode and no one preferred the VVIR. Cardiac output at rest (echo-Doppler method) was 4.7 +/- 1.4 versus 5.7 +/- 1.6 liter/min (P less than 0.01), body weight was 65.9 +/- 6.6 versus 64.9 +/- 6.1 kg (P less than 0.02), atrial natriuretic peptide was 236 +/- 112 versus 198 +/- 110 pg/mL (P less than 0.01), respectively, during VVIR and DDD modes. Effort tolerance was similar with the two modes of pacing (68 +/- 15 vs 70 +/- 18 watts/min).(ABSTRACT TRUNCATED AT 250 WORDS) more...
- Published
- 1990
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66. A carrot cell variant temperature sensitive for somatic embryogenesis reveals a defect in the glycosylation of extracellular proteins.
- Author
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Lo Schiavo F, Giuliano G, de Vries SC, Genga A, Bollini R, Pitto L, Cozzani F, Nuti-Ronchi V, and Terzi M
- Subjects
- Biological Transport, Blotting, Western, Fluoresceins, Glycosylation, Mannose metabolism, Phenotype, Plant Cells, Plants genetics, Plants metabolism, Temperature, Glycoproteins metabolism, Plant Proteins metabolism, Plants embryology
- Abstract
The temperature-sensitive carrot cell variant ts11c, arrested in somatic embryogenesis after the globular stage, was characterized. The sensitivity to a shift from 24 degrees C (permissive temperature) to 32 degrees C (non-permissive temperature) is greatest at the globular stage of embryogenesis, while cells proliferating in unorganized fashion and plantlets are not affected. Embryogenesis in ts11c is also arrested at the permissive temperature by replacement of conditioned culture medium with fresh medium. The timing of sensitivity of ts11c to medium replacement coincides with the sensitivity to temperature shift. Both sensitivities are recessive in somatic hybrids between ts11c and wild-type cells. Extracellular glycoproteins synthesized by ts11c at the non-permissive temperature contain much less fucose than those synthesized by the wild type. The glycoproteins synthesized by the variant under non-permissive conditions do not accumulate at the periphery of the embryo, as their wild-type counterparts do, but instead show a diffuse distribution throughout the embryo. The defect in ts11c can be fully complemented by the addition of extracellular wild-type proteins. A revertant of ts11c was isolated that simultaneously reacquired temperature insensitivity and normal glycosylation ability. Collectively, these observations indicate that ts11c is not able to perform proper glycosylation at the non-permissive temperature and suggest that the activity of certain extracellular proteins, essential for the transition of globular to heart stage somatic embryos, depends on the correct modification of their oligosaccharide side-chains. more...
- Published
- 1990
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67. [Contribution of computerized radioisotope angiocardiography to the diagnosis of arrhythmogenic dysplasia of the right ventricle].
- Author
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De Benedictis N, Bruna C, Biggi A, Bollini R, Farinelli C, Papaleo A, Tortore P, Rossetti G, Ugliengo G, and Camuzzini G
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- Adult, Bundle-Branch Block diagnosis, Cardiomyopathy, Hypertrophic complications, Cardiomyopathy, Hypertrophic physiopathology, Female, Heart Ventricles diagnostic imaging, Humans, Male, Middle Aged, Radionuclide Imaging, Cardiomyopathy, Hypertrophic diagnostic imaging, Tachycardia etiology
- Abstract
Radionuclide angiography phase analysis was performed in two patients presenting with recurrent right-sided ventricular tachycardia without angiographic evidence of valvular or ischemic heart disease. A dilated, poorly contracting (EF = 20%) right ventricle with localized dyskinetic areas was found in contrast with normal left ventricular function. The suggested diagnosis of Arrhythmogenic Right Ventricular Dysplasia was confirmed by right ventricular angiography performed in one patient. The diagnostic interest of radionuclide angiography phase analysis in patients with Arrhythmogenic Right Ventricular Dysplasia is stressed. more...
- Published
- 1984
68. Molecular analysis of a phytohemagglutinin-defective cultivar of Phaseolus vulgaris L.
- Author
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Vitale A, Ceriotti A, and Bollini R
- Abstract
The seeds of Phaseolus vulgaris cv. Pinto III are known to lack detectable amounts of phytohemagglutinin (PHA) and to accumulate very reduced levels of PHA mRNA compared with normal cultivars. Using PHA complementary-DNA clones and monospecific antibodies we analyzed cv. Pinto III genomic DNA and cotyledonary proteins synthesized both in vitro and in vivo. We detected genomic DNA sequences that hybridize with complementary-DNA clones for the two different classes of PHA polypeptides (PHA-E and PHA-L), at levels comparable to a normal bean cultivar. This indicates that the cv. Pinto III phenotype is not the result of a large deletion of the PHA structural genes. Messenger RNA isolated from cv. Pinto III developing cotyledons synthesizes in vitro very small amounts of a protein which is recognized by antibodies specific for PHA, and gives, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a single band with molecular weight similar but not identical to that of PHA-L polypeptides. This protein is also synthesized in vivo at a very reduced level, less than 1% compared with PHA in normal cultivars, and has mitogenic activity comparable to that of the PHA-L subunit, while it shows very weak erythroagglutinating activity. The initial steps in the synthesis and processing of this protein are identical to those already identified for PHA polypeptides. The cv. Pinto III protein could be either a PHA-L polypeptide whose synthesis is not affected by the mutation or a PHA-like lectin present normally at low levels in P. vulgaris. more...
- Published
- 1985
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69. The rough endoplasmic reticulum is the site of reserve-protein synthesis in developing Phaseolus vulgaris cotyledons.
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Bollini R and Chrispeels MJ
- Abstract
Cytyledons of the common bean, Phaseolus vulgaris L., were incubated with radioactive amino acids at different stages of seed development. The proteins were fractionated by ion-exchange chromatography, sucrose gradients, and sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis. From 16 to 28 d after flowering about 40% of the incorporated radioactivity was associated with the polypeptides of vicilin and 10% with those of phytohemagglutinin.Polysomes were isolated from developing cotyledons 20-25 d after flowering and free polysomes were separated from membrane-bound polysomes. Aurintricarboxylic acid, an inhibitor of initiation in cell-free translation systems, did not inhibit the incorporation of amino acids into in-vitro synthesized proteins, indicating that synthesis was limited to the completion of already initiated polypeptides. Autofluorography of SDS-polyacrylamide gels showed that the two classes of polysomes made two different sets of polypeptides and that there was little overlap between these two sets.Four polypeptides similar in size to the 4 polypeptides of vicilin were made by membrane-bound polysomes and not by free polysomes. Antibodies specific for vicilin bound to those 4 polypeptides. Free polysomes made only polypeptides which did not bind to antibodies specific for vicilin. Antibodies against phytohemagglutinin did not bind to any of the invitro synthesized polypeptides.The membranes to which the polysomes were bound were characterized on sucrose gradients and by electron microscopy. Polysomes recovered from membranes which banded on top of 35 and 50% sucrose synthesized the vicilin polypeptides most rapidly. These membrane fractions were rich in vesicles of rough endoplasmic reticulum (ER). The ER marker-enzyme NADH-cytochrome-c reductase banded with an average density of 1.18 g/cm(3) (40% w/w sucrose) on continuous gradients. These experiments demonstrate that the ER is the site of vicilin synthesis in developing bean cotyledons. Quantitative determinations of several ER parameters (RNA and lipid-phosphate content, NADH-cytochrome-c-reductase activity) show that expansion of the cotyledons is accompanied by a 4-6-fold increase in ER. more...
- Published
- 1979
- Full Text
- View/download PDF
70. Subcellular distribution and functional properties of different forms of elongation fractor EF1 from wheat embryos.
- Author
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Lanzani GA, Caldiroli E, Zocchi G, Manzocchi LA, Bollini R, and De Alberti L
- Subjects
- Binding Sites, Guanosine Triphosphate metabolism, Macromolecular Substances, Molecular Weight, Protein Binding, RNA, Transfer metabolism, Subcellular Fractions analysis, Subcellular Fractions metabolism, Triticum metabolism, Peptide Elongation Factors analysis, Plants metabolism, Ribosomes metabolism
- Abstract
Elongation factor EF1 was found in a low salt homogenate of wheat embryos, either in the 100 000 X g supernatant or in the ribosome pellet. The ribosome-linked EF1 (EF1R), deteched by high salt washing, was purified to electrophoretical homogenetiy and its molecular and functional properties compared to those of a purified high molecular weight species of EF1 obtained from cytoplasm (EF1H). The two forms are associations of different polypeptides having in common only the polypeptide which can form the ternary complex with aminoacyl-tRNA and GTP. Whereas EF1R is able to fulfill all the EF1 functions, EF1H, incubated with ribosomes completely deprived of elongation factors, can catalyze the aminoacyl-tRNA binding to ribosomes, but, in the presence of EF2, forms only a very small amount of poly(Phe). more...
- Published
- 1975
- Full Text
- View/download PDF
71. Synthesis of Lectin-Like Protein in Developing Cotyledons of Normal and Phytohemagglutinin-Deficient Phaseolus vulgaris.
- Author
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Vitale A, Zoppè M, Fabbrini MS, Genga A, Rivas L, and Bollini R
- Abstract
The genome of the common bean Phaseolus vulgaris contains a small gene family that encodes lectin and lectin-like proteins (phytohemagglutinin, arcelin, and others). One of these phytohemagglutinin-like genes was cloned by L. M. Hoffman et al. ([1982] Nucleic Acids Res 10: 7819-7828), but its product in bean cells has never been identified. We identified the product of this gene, referred to as lectin-like protein (LLP), as an abundant polypeptide synthesized on the endoplasmic reticulum (ER) of developing bean cotyledons. The gene product was first identified in extracts of Xenopus oocytes injected with either cotyledonary bean RNA or LLP-mRNA obtained by hybrid-selection with an LLP cDNA clone. A tryptic map of this protein was identical with a tryptic map of a polypeptide with the same SDS-PAGE mobility detectable in the ER of bean cotyledons pulse-labeled with either [(3)H]glucosamine or [(3)H]amino acids, both in a normal and in a phytohemagglutinin-deficient cultivar (cultivars Greensleeves and Pinto UI 111). Greensleeves LLP has M(r) 40,000 and most probably has four asparagine-linked glycans. Pinto UI 111 LLP has M(r) 38,500. Unlike phytohemagglutinin which is a tetramer, LLP appears to be a monomer by gel filtration analysis. Incorporation of [(3)H]amino acids indicates that synthesis of LLP accounts for about 3% of the proteins synthesized on the ER, a level similar to that of phytohemagglutinin. more...
- Published
- 1989
- Full Text
- View/download PDF
72. Mannose analog 1-deoxymannojirimycin inhibits the Golgi-mediated processing of bean storage glycoproteins.
- Author
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Vitale A, Zoppè M, and Bollini R
- Abstract
The asparagine-linked oligosaccharide chains of glycoproteins can be processed to form a wide variety of structures. The Golgi complex is the main compartment involved in this processing. In mammalian cells the first enzyme acting along the Golgi processing pathway is mannosidase I, whose action is a prerequisite for any further processing and which is inhibited by the mannose analog 1-deoxymannojirimycin (dMM). To have insights into the processing pathway in plant cells, we have studied the in vivo effect of dMM on the processing of the bean (Phaseolus vulgaris) storage proteins phaseolin and phytohemagglutinin, two well characterized plant glycoproteins. Cotyledons obtained from developing seeds were labeled with radioactive leucine, glucosamine, or fucose in the presence or absence of dMM. Treatment with dMM fully inhibited the acquisition of resistance to endo-beta-N-acetylglucosaminidase H by phaseolin and phytohemagglutinin and the incorporation of fucose into protein. Furthermore, the apparent molecular weight of the polypeptides of phaseolin and phytohemagglutinin synthesized in dMM-treated cotyledons was consistent with the exclusive presence of oligommanose oligosaccharide chains which had not been processed in the Golgi complex. The inhibition of processing did not prevent exit from the Golgi complex, and most probably the storage proteins were correctly targeted to the protein bodies as indicated by the post-translational polypeptide cleavage of phaseolin. These results indicate that the action of a mannosidase is the first obligatory step of Golgi-mediated processing also in a plant cell and, together with data obtained in other laboratories on the in vitro specificity of glycosidases and glycosyltransferases present in the Golgi complex of plant cells, support the hypothesis that the key early reactions in Golgi-mediated processing are similar if not identical in plants and mammals. more...
- Published
- 1989
- Full Text
- View/download PDF
73. 1-Deoxymannojirimycin inhibits Golgi-mediated processing of glycoprotein in Xenopus oocytes.
- Author
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Fabbrini MS, Zoppè M, Bollini R, and Vitale A
- Subjects
- 1-Deoxynojirimycin, Animals, Female, Glucosamine analogs & derivatives, Glucosamine pharmacology, Golgi Apparatus drug effects, Oocytes drug effects, Protein Biosynthesis, RNA, Messenger genetics, Xenopus, Glycoproteins genetics, Golgi Apparatus metabolism, Oocytes metabolism
- Abstract
We prepared in vitro an mRNA transcript coding for the erythroagglutinating subunit of the kidney bean glycoprotein phytohemagglutinin, E-PHA. The mRNA, injected into Xenopus oocytes, synthesized E-PHA carrying two Asn-linked carbohydrate chains, one of which was processed and acquired resistance to endo-beta-N-acetylglucosaminidase H, as occurs in the native bean cells. When the mannose analog 1-deoxymannojirimycin, an inhibitor of mammalian Golgi mannosidase I, was included in the oocyte culture medium, the acquisition of endo-beta-N-acetylglucosaminidase H resistance was abolished, indicating that also in an amphibian cell the inhibitor blocks a key reaction in Golgi-mediated processing. more...
- Published
- 1988
- Full Text
- View/download PDF
74. Contribution of processing events to the molecular heterogeneity of four banding types of phaseolin, the major storage protein of Phaseolus vulgaris L.
- Author
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Lioi L and Bollini R
- Abstract
The origin of the molecular heterogeneity of phaseolin was investigated by studying, both in vivo and in vitro, the synthesis and processing of four different banding types of phaseolin in five cultivars of Phaseolus vulgaris L. The results demonstrate: I) Newly-synthesized (unprocessed) phaseolin in all cultivars is composed of three major components. These differ between cultivars, both in charge and Mr. II) The processing of these precursors is highly conserved and consists of the co-translational cleavage of a signal peptide, two glycosylation steps in the endoplasmic reticulum and a further modification inside the protein bodies to give the mature form. III) Some of the molecular heterogeneity of each phaseolin banding type is due to a different extent of glycosylation of its polypeptide components. more...
- Published
- 1984
- Full Text
- View/download PDF
75. Characteristics of Membrane-Bound Lectin in Developing Phaseolus vulgaris Cotyledons.
- Author
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Chrispeels MJ and Bollini R
- Abstract
Cotyledons of developing Phaseolus vulgaris L. cv Greensleeves seeds were labeled for 2 to 3 hours with (3)H-amino acids, and newly synthesized phytohemagglutinin (PHA) was isolated by affinity chromatography with thyroglobulin-Sepharose. The presence of 1% Tween in the homogenate increased the yield of radioactive PHA by 50 to 100%. Isopycnic sucrose gradients were used to show that this detergent-released PHA was associated with the endoplasmic reticulum (ER), and pulse-chase experiments showed that the half-life of the PHA in the ER was 90 to 120 minutes. Since PHA is transiently associated with the ER and accumulates in protein bodies, we postulate that this rapidly turning over pool of PHA in the ER represents protein en route to the protein bodies. The PHA in the ER has the same sedimentation constant as mature PHA and is capable of agglutinating red blood cells. The observations substantiate earlier claims that plant cells contain membrane-bound lectins. However, they also indicate that these lectins are not necessarily functional components of the membranes with which they are associated, but may represent transport pools of lectin normally localized in other cellular compartments. more...
- Published
- 1982
- Full Text
- View/download PDF
76. Biosynthesis and processing of phytohemagglutinin in developing bean cotyledons.
- Author
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Vitale A, Ceriotti A, Bollini R, and Chrispeels MJ
- Subjects
- Endoplasmic Reticulum metabolism, Fabaceae growth & development, Golgi Apparatus metabolism, Mannose metabolism, Oligosaccharides metabolism, Plant Lectins, Polyribosomes metabolism, Protein Biosynthesis, Protein Processing, Post-Translational, Spectrometry, Fluorescence, Tunicamycin pharmacology, Fabaceae metabolism, Phytohemagglutinins biosynthesis, Plants, Medicinal
- Abstract
Phytohemagglutinin (PHA) is a family of tetrameric isolectins which accumulate in the protein bodies of developing Phaseolus vulgaris cotyledons. Each tetramer contains erythroagglutinating (E) or lymphocyte-mitogenic (L) subunits, or a combination of both. The subunits have Mr around 33000, E being slightly larger than L. Phytohemagglutinin is a glycoprotein, and its carbohydrate moiety contains N-acetylglucosamine, mannose, fucose and xylose, indicating that this protein has complex oligosaccharide sidechains. Several steps in the biosynthesis and in the cotranslational and post-translational processing of the glycopolypeptides of PHA have been identified. The polypeptides of PHA are synthesized by polysomes attached to the endoplasmic reticulum. The glycosylation of the polypeptides is a cotranslational process, in which each PHA polypeptide usually acquires two oligosaccharide sidechains. The oligosaccharides of PHA isolated from the endoplasmic reticulum are susceptible to digestion with alpha-mannosidase and endo-beta-N-acetylglucosaminidase H indicating that they are of the high-mannose type. In the presence of tunicamycin two unglycosylated polypeptides of PHA are synthesized, indicating that the differences in Mr between the E and L subunits of PHA are not due to differences in glycosylation alone. Transport of PHA to the protein bodies is mediated by the Golgi apparatus where at least part of the oligosaccharide chains of PHA are modified [ Chrispeels , M. J. (1983) Planta ( Berl .) 157, 454-461, and 158, 140-151]. The modified oligosaccharide chains of PHA are then gradually trimmed to a smaller size when the protein is already in the protein bodies. This processing results in an increase in the mobility of the PHA subunits in denaturing polyacrylamide gels. more...
- Published
- 1984
- Full Text
- View/download PDF
77. [Work capacity evaluation in patients with valvular prostheses].
- Author
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De Benedictis N, Bollini R, Meinardi F, and Rebella R
- Subjects
- Aortic Valve, Echocardiography, Electrocardiography, Exercise Test, Humans, Mitral Valve, Tomography, X-Ray Computed, Disability Evaluation, Heart Valve Prosthesis rehabilitation, Work Capacity Evaluation
- Abstract
The possibility of evaluating the capacity for work of subjects wearing heart valve prostheses is analysed. The many factors affecting the return to normal life after operations for valvulopathies are not considered. In strictly medical terms cardiac terms cardiac function can be adequately evaluated by anamnestic and clinical surveys, supplemented by standard non-surgical instrumental examination with particular emphasis on echography, computerised radioisotope angiocardiography and physical exertion tests. more...
- Published
- 1983
78. In vivo and in vitro processing of seed reserve protein in the endoplasmic reticulum: evidence for two glycosylation steps.
- Author
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Bollini R, Vitale A, and Chrispeels MJ
- Subjects
- Glucosamine metabolism, Glycopeptides metabolism, In Vitro Techniques, Mannose metabolism, Polyethylene Glycols pharmacology, Protein Biosynthesis, Tunicamycin pharmacology, Endoplasmic Reticulum metabolism, Protein Processing, Post-Translational
- Abstract
Cotyledons of the common bean (Phaseolus vulgaris L.) synthesize large amounts of the reserve protein phaseolin. The polypeptides are synthesized on membrane-bound polysomes, pass through the endoplasmic reticulum (ER) and accumulate in protein bodies. For a study of the biosynthesis and processing of phaseolin, developing cotyledons were labeled with radioactive amino acids, glucosamine and mannose, and isolated fractions (polysomal RNA, polysomes, and rough ER) were used for in vitro protein synthesis. Newly synthesized phaseolin present in the ER of developing cotyledons can be fractioned into four glycopolypeptides by SDS PAGE. In vitro synthesis with polysomal RNA results in the formation of two polypeptides by polysome run-off shows that glycosylation is a co-translational event. The two unglycosylated polypeptides formed by polysome run-off are slightly smaller than the two polypeptides formed by in vitro translation of isolated RNA, indicating that a signal peptide may be present on these polypeptides. Run-off synthesis with rough ER produces a pattern of four polypeptides similar to the one obtained by in vivo labeling. The two abundant glycopolypeptides formed by polysome run-off. This result indicates the existence of a second glycosylation event for the abundant polypeptides. Inhibition of glycosylation by Triton X-100 during chain-completion with rough ER was used to show that these two glycosylation steps normally occur sequentially. Both glycosylation steps are inhibited by tunicamycin. Analysis of carhohydrate to protein ratios of the different polypeptides and of trypsin digests of polypeptides labeled with [(3)H]glucosamine confirmed the conclusion that some glycosylated polypeptides contain two oligosaccharide chains, while others contain only one. An analysis of tryptic peptide maps shows that each of the unglycosylated polypeptides is the precursor for one glycosylated polypeptide with one oligosaccharide chain and one with two oligosaccharide chains. more...
- Published
- 1983
- Full Text
- View/download PDF
79. Regulation of processing of a plant glycoprotein in the Golgi complex: A comparative study usingXenopus oocytes.
- Author
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Vitale A, Sturm A, and Bollini R
- Abstract
The synthesis of phytohemagglutinin (PHA), the major seed lectin ofPhaseolus vulgaris, was investigated inXenopus oocytes injected with RNA isolated from developing bean cotyledons. As is the case for normal PHA, oocyte-synthesized PHA polypeptides were found to contain two asparagine-linked oligosaccharide chains, one of which was of the high-mannose type and the other one of the Golgi-modified type, being largely resistant to endo-β-N-acetylglucosaminidase H digestion and containing fucose. The modified oligosaccharide chain of oocyte-synthesized PHA appeared to be much larger and more heterogeneous with respect to the modified chain normally present on PHA. When the oocytes were injected with purified mRNA for PHA, isolated by hybrid-selection using a PHA complementary-DNA clone, the results were the same as those obtained by injecting total cotyledonary RNA. On the whole, these results indicate that plant glycoproteins are directed to the Golgi complex even when synthesized in an animal cell, and that correct sorting of the oligosaccharide chains to be processed is independent of the cell-type in which protein synthesis occurs. The form of processing is however cell-type specific. more...
- Published
- 1986
- Full Text
- View/download PDF
80. The position of the oligosaccharide side-chains of phytohemagglutinin and their accessibility to glycosidases determines their subsequent processing in the Golgi.
- Author
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Faye L, Sturm A, Bollini R, Vitale A, and Chrispeels MJ
- Subjects
- Concanavalin A metabolism, Endoplasmic Reticulum analysis, Fucose metabolism, Glucosamine metabolism, Hexosaminidases pharmacology, Mannosidases pharmacology, Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase, Molecular Weight, Protein Denaturation, alpha-Mannosidase, Glycoside Hydrolases pharmacology, Golgi Apparatus metabolism, Oligosaccharides metabolism, Phytohemagglutinins metabolism
- Abstract
Phytohemagglutinin (PHA), the glycoprotein lectin of Phaseolus vulgaris has two types of asparagine-linked oligosaccharides per polypeptide: a high-mannose chain with the formula (Man)8-9(GlcNAc)2 on Asn12 and a modified chain with fewer mannose residues and additional fucose and xylose residues on Asn60. Glycosylation of PHA is a cotranslational process, which occurs in the endoplasmic reticulum, and newly synthesized PHA has two high-mannose chains. Transport of PHA to the protein bodies via the Golgi complex is accompanied by the modification of one of the two high-mannose chains. Why is only one chain modified, while the other remains in the high-mannose configuration? By determining the effect of digestion with various glycosidases (alpha-mannosidase, endo-beta-N-acetylglucosaminidase H and endo-beta-N-acetylglucosaminidase F) on native and denatured PHA we obtained evidence consistent with the interpretation that the accessibility of oligosaccharide chains to modifying enzymes is of major importance in determining whether a high-mannose chain becomes modified or not. The high-mannose chain of mature undenatured PHA is only partially accessible to glycosidases, while PHA obtained from the endoplasmic reticulum has one high-mannose chain, which is readily accessible to alpha-mannosidase and endoglycosidases H and F. We show that this readily accessible chain is in the same position on the polypeptide (Asn60) as the modified oligosaccharide on mature PHA. Thus, accessibility of the oligosaccharide side-chains to processing enzymes in the Golgi determines whether a particular oligosaccharide side-chain is processed or not. more...
- Published
- 1986
- Full Text
- View/download PDF
81. The influence of cyclic GMP on polypeptide synthesis in a cell-free system derived from wheat embryos.
- Author
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Lanzani GA, Giannattasio M, Manzocchi LA, Bollini R, Soffientini AN, and Macchia V
- Subjects
- Carbon Radioisotopes, Cell-Free System, Chromatography, Gel, Guanine Nucleotides, Peptide Biosynthesis, Peptide Chain Elongation, Translational drug effects, Peptide Elongation Factors, Phenylalanine, Plant Cells, Plants drug effects, Poly U metabolism, RNA, Transfer metabolism, Ribosomes drug effects, Ribosomes metabolism, Spectrophotometry, Ultraviolet, Stimulation, Chemical, Triticum cytology, Triticum drug effects, Triticum metabolism, Tritium, Cyclic GMP pharmacology, Plant Proteins biosynthesis, Plants metabolism
- Published
- 1974
- Full Text
- View/download PDF
82. Characterization and subcellular localization of vicilin and phytohemagglutinin, the two major reserve proteins of Phaseolus vulgaris L.
- Author
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Bollini R and Chrispeels MJ
- Abstract
Extracts of bean (Phaseolus vulgaris L. cv. Greensleeves) cotyledons contained two abundant proteins: vicilin and phytohemagglutinin. Vicilin, a 6.9 S protein fraction at neutral pH, associated to an 18.0 S form at pH 4.5 and had 3 non-identical subunits with molecular weights (MW) of 52,000, 49,000 and 46,000. Phytohemagglutinin, a 6.4 S protein fraction, had 2 non-identical subunits with MW of 34,000 and 36,000. Phytohemagglutinin could be separated by isoelectrofocusing into a mitogenic and non-erythroagglutinating protein with a single subunit of MW=34,000, and a mitogenic and erythroagglutinating protein fraction which contained both subunits. Vicilin is apparently identical with the so called glycoprotein II (A. Pusztai and W.B. Watt, Biochim. Biophys. Acta 365, 57-71, 1970) and with globulin G1 (R.C. McLeester, T.C. Hall, S.M. Sun, F.A. Bliss, Phytochem. 2, 85; 1973), while phytohemagglutinin is identical with globulin G2 (McLeester et al., 1973). Since vicilin and phytohemagglutinin are internationally used names there is no need to introduce new names to describe P. vulgaris reserve proteins. Both proteins are catabolized in the course of seedling growth and are located in the protein bodies, indicating that they are reserve proteins. Vicilin isolated in its 18.0 S form from the cotyledons of young seedlings contains substantial quantities of smaller polypeptides, in addition the 3 original ones. We suggest that the presence of these small polypeptides represents partial breakdown of the vicilin prior to its complete catabolism. more...
- Published
- 1978
- Full Text
- View/download PDF
83. The translational system from wheat embryos: some properties of the polypeptides associated in EF1H.
- Author
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Lanzani GA, Caldiroli E, Manzocchi LA, Bollini R, and Albertie LDe
- Subjects
- Molecular Weight, Peptide Biosynthesis, Peptide Chain Elongation, Translational, Poly A, Poly U, Ribosomes metabolism, Triticum metabolism, Peptide Elongation Factors, Plant Proteins biosynthesis, Protein Biosynthesis, Seeds metabolism
- Published
- 1976
- Full Text
- View/download PDF
84. Some molecular properties of the elongation factor EF1 from wheat embryos.
- Author
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Bollini R, Soffientini AN, Bertani A, and Lanzani GA
- Subjects
- Carbon Radioisotopes, Chromatography, Chromatography, Gel, Deuterium, Electrophoresis, Disc, Guanosine Triphosphate, Hydroxyapatites, Molecular Weight, Phenylalanine, Protein Biosynthesis, RNA, Transfer, Ribosomes metabolism, Sodium Dodecyl Sulfate, Triticum analysis, Tritium, Ultracentrifugation, Peptide Elongation Factors isolation & purification, Plants analysis
- Published
- 1974
- Full Text
- View/download PDF
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