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There are three main disadvantages including time-consuming task, high cost and complex detection procedures in the semen quality measurement to heighten the roosters’ reproductive capability in breeder flocks. Another solution is to select the breeder roosters with fine phenotypic characteristics by humans, while it is also a considerably labor-intensive task and even increases the risk of zoonoses at a poultry farm. To solve these problems, this paper proposes a strategy that effective promoting factors applied to Progressive Multi-Granularity (PMG) network ensures the accuracy of entire image and improves the accuracy of fine-grained image. This strategy allows the basic networks boost the classification performance in the case of specific combination. Given the same images inputted into our model, two groups of questionnaires for practitioners and non-practitioners judging the fertility by the rooster’s phenotypic traits, the experimental results show that our method has raised the accuracy by almost 10% by comparison with the results of questionnaire survey.

G protein-coupled receptor 50 (GPR50) belongs to the G protein-coupled receptor which is highly homologous with the sequence of melatonin receptor MT1 and MT2. GPR50 expression has previously been reported in many brain regions, like cortex, midbrain, pons, amygdala. But, the distribution of GPR50 in the hippocampus and cortex and the cell types expressing GPR50 is not yet clear. In this study, we examined the distribution of GPR50 in adult male mice by immunofluorescence. Our results showed that GPR50 was localized in the CA1-3 pyramidal cells and the granule cells of the dentate gyrus. GPR50 was also expressed in excitatory and inhibitory neurons. As inhibitory neurons also contain many types, we found that GPR50 was localized in some interneurons in which it was co-expressed with the calcium-binding proteins calbindin, calretinin, and parvalbumin. Besides, similar results were seen in the cortex. The widespread expression of GPR50 in the hippocampus and cortex suggests that GPR50 may be associated with synaptic plasticity and cognitive function.

A lot of literature show that social isolation stress could be a key reason that leads to cognitive deficits for both humans and rodent models; however, the detailed mechanisms are still not clear completely. ADAR1 (Adenosine deaminase acting on RNA) is an enzyme involved in RNA editing that has a close relation to cognitive function. We hypothesize that social isolation stress may impact the expression of ADAR1, leading to cognitive deficits. To prove our hypothesis, we evaluated the cognition ability of the mice isolated for different durations (2, 4, and 8 weeks) using object recognition and object location tests; we also measured ADAR1 expressions in hippocampus and cortex using immunohistochemistry and western blot. Our study showed that social isolation stress significantly induced spatial and non-spatial cognition deficits. In addition, social isolation significantly increased both the immuno reactivity and protein expressions of ADAR1 in the hippocampus and frontal cortex. Furthermore, we found that adolescent re-socialization recovered not only the cognition deficits but also the increased ADAR1 protein expression in hippocampus and the increased number of ADAR1 positive cells in frontal cortex of the isolated mice. In conclusion, social isolation stress significantly increased ADAR1 expressions in the hippocampus and cortex, leading to cognitive deficits.

Adenosine deaminase acting on RNA (ADAR) activity increases in response to inflammation. Social isolation stress is related to neuroinflammation; however, it remains unclear whether ADAR1 is altered in response to social isolation stress-induced cognitive deficits. To investigate our hypothesis that ADAR1 displayed patterns of change in response to social isolation stress, we addressed this issue systemically by isolating Kunming mice for 2, 4 and 8 weeks individually since postnatal 21 days to set up isolation mouse model. Furthermore, we arranged re-socialization group to evaluate the alterations of ADAR1 in the cognitive deficits recovery. The results of behavior tests showed that social isolation stress resulted in cognitive dysfunction, which was recovered by re-socialization in re-gregarious rearing group. Furthermore, the immunohistochemistry and western blot results displayed that both the immunoreactivity and protein expression of ADAR1 in the hippocampus and frontal cortex increased obviously as compared to the same age mice without isolation. The above abnormal alterations of ADAR1 were recovered by re-socialization in re-gregarious rearing group. Our study supports the hypothesis that ADAR1 is altered in mice affected by social isolation stress-induced cognitive deficits.

Introduction Social isolation enhances the aggressive behavior of animals, but the detailed mechanism remains unclear. Epigenetic studies have suggested that Htr2c RNA editing is closely related to aggressive behavior. This study aims to obtain a fundamental understanding of how social isolation impacts adenosine deaminase acting on RNA 1 (ADAR1, RNA editing enzyme) and Htr2c RNA editing, leading to aggressive behavior, and explore the effective solutions for the recovery of this behavior. Methods We evaluated 21-day-old BALB/c mice with and without isolation for aggressive behavior using a resident-intruder test. Immune-reactivity and protein expression of ADAR1 (p110) were measured using immunohistochemistry and Western blotting. Htr2c RNA editing was evaluated using pyrosequencing. In addition, the 5-HT 2C R antagonist SB243213/5-HT 2C R inverse agonist SB206553 was used to treat the isolated mice, and the performance of both treatments on the behavior, ADAR1 (p110) expression, and Htr2c RNA editing in isolated mice was examined. Results Both the protein expression and immune-reactivity of ADAR1 (p110) in the amygdala decreased, but the percentage of Htr2c RNA editing at A and B sites of amygdala only showed a moderate increase in isolated BALB/c mice with enhanced aggressive behavior compared to the age-matched group-housed BALB/c mice. Additionally, treatment with the 5-HT 2C R antagonist SB243213/5-HT 2C R inverse agonist SB206553 recovered the enhanced aggressive behavior of isolated mice and returned the protein expression and immune-reactivity of ADAR1 (p110) back to the normal level. Moreover, compared to the age-matched isolated mice treated with physiological saline, isolated mice treated with 5-HT 2C R inverse agonist SB206553 showed a lower percentage of Htr2c RNA editing at both A and B sites, and the same result occurred in isolated mice treated with 5-HT 2C R antagonist SB243213 at B site of Htr2c RNA editing. Conclusions The 5-HT 2C R antagonist SB243213/5-HT 2C R inverse agonist SB206553 recovered increased aggressive behavior of isolated BALB/c mice mediated by ADAR1 (p110) expression and Htr2c RNA editing.

Protein protease inhibitors could potentially be used to stabilize proteases in commercial products such as liquid laundry detergents. However, many protein protease inhibitors are susceptible to hydrolysis inflicted by the protease. We have engineered Streptomyces subtilisin inhibitor (SSI) to resist proteolysis by adding an interchain disulfide bond and removing a subtilisin cleavage site at leucine 63. When these stabilizing changes were combined with changes to optimize the affinity for subtilisin, the resulting inhibitor provided complete protease stability for at least 5 months at 31 degrees C in a subtilisin-containing liquid laundry detergent and allowed full recovery of the subtilisin activity upon the dilution that occurs in a North American washing machine.

The Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a FADD-like interferon converting enzyme or caspase 8 (FLICE) inhibitory protein (vFLIP) that prevents death receptor-mediated apoptosis by inhibiting the recruitment and activation of FLICE. Since vFLIP physically interacts with tumor necrosis factor receptor associated factor 2 (TRAF2) and TRAF2 mediates activation of the jun NH(2)-terminal kinase (JNK)/activation protein 1 (AP1) pathway, we hypothesized that vFLIP might also activate this pathway. To evaluate this hypothesis, we transiently and stably transfected a vFLIP expression construct and performed several complementary assays to document that vFLIP activates the JNK/AP1 pathway and does so in a TRAF-dependent fashion. As vFLIP also activates the nuclear factor kappaB (NF-kappaB) signaling pathway and the NF-kappaB and JNK/AP1 pathways both modulate cellular interleukin-6 (cIL-6) expression, we postulated that vFLIP induces expression of this cytokine. We show that vFLIP induces cIL-6 expression and activates the cIL-6 promoter, and maximal activation of the cIL-6 promoter by vFLIP requires NF-kappaB and AP1 activation. In addition, vFLIP and latency-associated nuclear antigen (LANA), another KSHV-encoded latent protein, potentiate each other's ability to activate the cIL-6 promoter. Gene silencing experiments by RNA interference demonstrate that vFLIP in BCBL-1 endogenously infected primary effusion lymphoma (PEL) cells mediates JNK/AP1 activation and cIL-6 expression. Thus, we conclude that vFLIP, in addition to its known effects on NF-kappaB activation, also modulates the JNK/AP1 pathway and induces gene expression from the cIL-6 promoter in a JNK/AP1-dependent fashion.

A proteomic analysis was performed comparing normal rat soleus muscle to soleus muscle that had undergone either 0.5, 1, 2, 4, 7, 10 and 14 days of hindlimb suspension-induced atrophy or hindlimb suspension-induced atrophied soleus muscle that had undergone 1 hour, 8 hour, 1 day, 2 day, 4 day and 7 days of reweighting-induced hypertrophy. Muscle mass measurements demonstrated continual loss of soleus mass occurred throughout the 21 days of hindlimb suspension; following reweighting, atrophied soleus muscle mass increased dramatically between 8 hours and 1 day post reweighting. Proteomic analysis of normal and atrophied soleus muscle demonstrated statistically significant changes in the relative levels of 29 soleus proteins. Reweighting following atrophy demonstrated statistically significant changes in the relative levels of 15 soleus proteins. Protein identification using mass spectrometry was attempted for all differentially regulated proteins from both atrophied and hypertrophied soleus muscle. Five differentially regulated proteins from the hindlimb suspended atrophied soleus muscle were identified while five proteins were identified in the reweighting-induced hypertrophied soleus muscles. The identified proteins could be generally grouped together as metabolic proteins, chaperone proteins and contractile apparatus proteins. Together these data demonstrate that coordinated temporally regulated changes in the skeletal muscle proteorne occur during disuse-induced soleus muscle atrophy and reweighting hypertrophy.

Kinetic interactions of β-lactam antibiotics such as penicillin-G and cefotaxime with normal, penicillin-susceptible PBP2x from Streptococcus pneumoniae and a penicillin-resistant PBP2x (PBP2xR) from a resistant clinical isolate (CS109) of the bacterium have been extensively characterized using electrospray mass spectrometry coupled with a fast reaction (quench flow) technique. Kinetic evidence for a two-step acylation of PBP2x by penicillin-G has been demonstrated, and the dissociation constant, K d of 0.9 mm, and the acylation rate constant, k 2 of 180 s−1, have been determined for the first time. The millimolar range K d implies that the β-lactam fits to the active site pocket of the penicillin-sensitive PBP rather poorly, whereas the extremely fast k 2 value indicates that this step contributes most of the binding affinity of the β-lactam. The values of K d (4 mm) and k 2 (0.56 s−1) were also determined for PBP2xR. The combined value ofk 2/K d, known as overall binding efficiency, for PBP2xR (137m −1 s−1) was over 1000-fold slower than that for PBP2x (200,000 m −1s−1), indicating that a major part is played by the acylation steps in penicillin resistance. Most of the decreased binding efficiency of PBP2xR comes from the decreased (∼300-fold)k 2. Kinetic studies of cefotaxime acylation of the two PBP2x proteins confirmed all of the above findings. Deacylation rate constants (k 3) for the third step of the interactions were determined to be 8 × 10−6s−1 for penicilloyl-PBP2x and 5.7 × 10−4 s−1 for penicilloyl-PBP2xR, corresponding to over 70-fold increase of the deacylation rate for the resistant PBP2xR. Similarly, over 80-fold enhancement of the deacylation rate was found for cefotaxime-PBP2xRcomplex (k 3 = 3 × 10−4s−1) as compared with that of cefotaxime-PBP2x complex (3.5 × 10−6 s−1). This is the first time that such a significant increase ofk 3 values was found for a β-lactam-resistant penicillin-binding protein. These data indicate that the deacylation step also plays a role, which is much more important than previously thought, in PBP2xR resistance to β-lactams.

A proteomic analysis was performed comparing normal rat soleus muscle to denervated soleus muscle at 0.5, 1, 2, 4, 6, 8 and 10 days post denervation. Muscle mass measurements demonstrated that the times of major mass changes occurred between 2 and 4 days post denervation. Proteomic analysis of the denervated soleus muscle during the atrophy process demonstrated statistically significant (at the p < 0.01 level) changes in 73 soleus proteins, including coordinated changes in select groups of proteins. Sequence analysis of ten differentially regulated proteins identified metabolic proteins, chaperone and contractile apparatus proteins. Together these data indicate that coordinated temporally regulated changes in the proteome occur during denervation-induced soleus muscle atrophy, including changes in muscle metabolism and contractile apparatus proteins.

We analyzed protein expression in the cytosolic fraction prepared from whole kidneys in male Swiss-Webster mice exposed 1 h/day for five days to aerosolized JP-8 jet fuel at a concentration of 1000 mg/m3, simulating military occupational exposure. Kidney cytosol samples were solubilized and separated via large-scale, high-resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant changes in soluble kidney proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass finger-printing and related to ultrastructural abnormalities, altered protein processing, metabolic effects, and paradoxical stress protein/detoxification system responses. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression in the kidney and provide novel molecular evidence of JP-8 nephrotoxicity. Human risk is suggested by these data but conclusive assessment awaits a noninvasive search for biomarkers in JP-8 exposed humans.

We analyzed protein expression in the cytosolic fraction prepared from whole lung tissue in male Swiss-Webster mice exposed 1 h/day for seven days to aerosolized JP-8 jet fuel at concentrations of 1000 and 2500 mg/m3, simulating military occupational exposure. Lung cytosol samples were solubilized and separated via large scale, high resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant quantitative and qualitative changes in tissue cytosol proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass fingerprinting, confirmed by sequence tag analysis, and related to impaired protein synthetic machinery, toxic/metabolic stress and detoxification systems, ultrastructural damage, and functional responses to CO2 handling, acid-base homeostasis and fluid secretion. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression and corroborate previous morphological and biochemical evidence. Further molecular marker development and mechanistic inferences from these observations await proteomic analysis of whole tissue homogenates and other cell compartment, i.e., mitochondria, microsomes, and nuclei of lung and other targets.

Penicillin-binding protein 2a (PBP2a) is the primary beta-lactam resistance determinant of methicillin-resistant Staphylococcus aureus (MRSA). MecA, the gene coding for PBP2a, was cloned with the membrane-anchoring region at the N-terminus deleted. The truncated protein (PBP2a) was overexpressed in Escherichia coli mostly in the soluble form accounting for approximately 25% of soluble cell protein and was purified to homogeneity. The purified protein was shown to covalently bind beta-lactams in an 1:1 ratio as determined by electrospray mass spectrometry. A novel method based on HPLC-elctrospray mass spectrometry has been developed to quantitatively determine the formation of the covalent adducts or acyl-PBP2a complexes. By using this method, combined with kinetic techniques including quench flow, we have extensively characterized the interactions between PBP2a and three beta-lactams and determined related kinetic parameters for the first time. The apparent first-order rate constants (ka) of PBP2a acylation by benzylpenicillin showed a hyperbolic dependence on the concentration of benzylpenicillin. This is consistent with the mechanism that the binding of the penicillin to PBP2a consists of reversible formation of a Michaelis complex followed by formation of the penicilloyl-PBP2a adduct, and allowed the determination of the individual kinetic parameters for these two steps, the dissociation constant Kd of 13.3 mM and the first-order rate constant k2 of 0.22 s-1. From these values, the second-order rate constant k2/Kd, the value reflecting the overall binding efficiency of a beta-lactam, of 16.5 M-1 s-1 was obtained. The fairly high Kd value indicates that benzylpenicillin fits rather poorly into the protein active site. Similar studies on the interaction between PBP2a and methicillin revealed k2 of 0.0083 s-1 and Kd of 16.9 mM, resulting in an even smaller k2/Kd value of 0.49 M-1 s-1. The rate constants k3 for deacylation of the acyl-PBP2a complexes, the third step in the interactions, were measured to be

Penicillin-binding protein 2a (PBP2a), a high molecular mass PBP, is the primary enzyme responsible for the β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA). Inhibition of a PBP such as PBP2a by β-lactams is due to covalent modification of an active site serine residue. Based on the sequence alignment with well studied β-lactamases, DD-carboxypeptidases and other high molecular mass PBPs, the serine of a tetrad S403XXK in PBP2a was tentatively identified as the penicillin-binding site. However, direct evidence for the involvement of serine403 has not been reported. In this study, a method which combines liquid chromatography/electrospray mass spectrometry (LC/MS) and nano-electrospray MS for the identification of the active site serine in PBP2a is described. The covalent binding of the β-lactams was carried out in vitro with the recombinant PBP2a. Peptide mapping of the cyanogen bromide fragments from penicilloyl-PBP2a, using microbore LC/MS, provided a rapid identification of the modified peptide with a 334 Da mass increase. The acylated peptide was isolated and further digested with trypsin. Nano-electrospray MS/MS sequencing of the acylated peptide in the tryptic digest showed that the penicillin was indeed attached to serine403. © 1998 John Wiley & Sons, Ltd.

It has been reported that social isolation stress could be a key factor that leads to cognitive deficit for both humans and rodent models. However, detailed mechanisms are not yet clear. ADAR1 (Adenosine deaminase acting on RNA) is an enzyme involved in RNA editing that has a close relation to cognitive function. We have hypothesized that social isolation stress may impact the expression of ADAR1 in the brain of mice with cognitive deficit. To test our hypothesis, we evaluated the cognition ability of mice isolated for different durations (2, 4, and 8 weeks) using object recognition and object location tests; we also measured ADAR1 expression in hippocampus and cortex using immunohistochemistry and western blot. Our study showed that social isolation stress induced spatial and non-spatial cognition deficits of the tested mice. In addition, social isolation significantly increased both the immunoreactivity and protein expression of ADAR1 (p110) in the hippocampus and frontal cortex. Furthermore, re-socialization could not only recover the cognition deficits, but also bring ADAR1 (p110) immunoreactivity of hippocampus and frontal cortex, as well as ADAR1 (p110) protein expression of hippocampus back to the normal level for the isolated mice in adolescence. In conclusion, social isolation stress significantly increases ADAR1 (p110) expression in the hippocampus and frontal cortex of the mice with cognitive deficit. This finding may open a window to better understand the reasons (e.g., epigenetic change) that are responsible for social isolation-induced cognitive deficit and help the development of novel therapies for the resulted diseases.

The oxidation of ascorbic acid leads to the formation of several compounds which are capable of reacting with protein amino groups via a Maillard reaction. Radioactivity from [1- 14 C]ascorbic acid was linearly incorporated into lens crystallins over a 10 day period in the presence of NaCNBH 3 . This rate of incorporation was 6–7-fold more rapid than that obtained with [[ 14 C]glucose under the same conditions. SDS-PAGE showed a linear incorporation into all the cyrstallin subunits. [1- 14 ]Ascorbic acid-label led α-crystallin was separated into into its component A and B subunits, and each was digested with chymotrypsin. HPLC peptide analysis showed a differential labelling of the various lysine residues. Analysis of the peptides by mass spectrometry allowed the identification of the sites and the extent of modification. These values ranged from 6% for Lys-78 to 36% for Lys-11 in the A subunit and from 5% for Lys-82 to an average of 38% for the peptide containing Lys-166, Lys-174 and Lys-175 in the B subunit. Amino acid analysis demonstrated a single modification reaction producing N ϵ -(carboxymethyl)lysine. This agreed with the mass increase of 58 observed for each modified peptide.

Prior studies suggest Staphylococcus aureus exotoxins are not produced when the organism is cultured in human blood. Human blood was fractionated into plasma and water-lysed red blood cells, and it was demonstrated that mixtures of alpha and beta globins of hemoglobin (as low as 1 mug/mL) inhibited S. aureus exotoxin production while increasing production of protein A and not affecting bacterial growth. Pepsin but not trypsin digestion destroyed the ability of alpha and beta globin to inhibit exotoxin production. Exotoxin production by both methicillin-resistant and methicillin-susceptible organisms was inhibited. Production of streptococcal pyrogenic exotoxin A by Streptococcus pyogenes was unaffected by alpha and beta globin chains but was inhibited when produced in S. aureus. Use of isogenic S. aureus strains suggested the targets of alpha and beta globin chains, leading to inhibition of staphylococcal exotoxins, included the two-component system SrrA-SrrB. delta hemolysin production was also inhibited, suggesting the two-component (and quorum sensing) system AgrA-AgrC was targeted. The alpha and beta globin chains represent promising molecules to interfere with the pathogenesis of serious staphylococcal diseases.

Fungi in the genus Malassezia are ubiquitous skin residents of humans and other warm-blooded animals. Malassezia are involved in disorders including dandruff and seborrheic dermatitis, which together affect >50% of humans. Despite the importance of Malassezia in common skin diseases, remarkably little is known at the molecular level. We describe the genome, secretory proteome, and expression of selected genes of Malassezia globosa . Further, we report a comparative survey of the genome and secretory proteome of Malassezia restricta , a close relative implicated in similar skin disorders. Adaptation to the skin environment and associated pathogenicity may be due to unique metabolic limitations and capabilities. For example, the lipid dependence of M. globosa can be explained by the apparent absence of a fatty acid synthase gene. The inability to synthesize fatty acids may be complemented by the presence of multiple secreted lipases to aid in harvesting host lipids. In addition, an abundance of genes encoding secreted hydrolases (e.g., lipases, phospholipases, aspartyl proteases, and acid sphingomyelinases) was found in the M. globosa genome. In contrast, the phylogenetically closely related plant pathogen Ustilago maydis encodes a different arsenal of extracellular hydrolases with more copies of glycosyl hydrolase genes. M. globosa shares a similar arsenal of extracellular hydrolases with the phylogenetically distant human pathogen, Candida albicans , which occupies a similar niche, indicating the importance of host-specific adaptation. The M. globosa genome sequence also revealed the presence of mating-type genes, providing an indication that Malassezia may be capable of sex.

Peptide vaccines able to induce high affinity and protective neutralizing antibodies must rely in part on the design of antigenic epitopes that mimic the three-dimensional structure of the corresponding region in the native protein. We describe the design, structural characterization, immunogenicity, and neutralizing potential of antibodies elicited by conformational peptides derived from the human T-cell leukemia virus type 1 (HTLV-1) gp21 envelope glycoprotein spanning residues 347-374. We used a novel template design and a unique synthetic approach to construct two peptides (WCCR2T and CCR2T) that would each assemble into a triple helical coiled coil conformation mimicking the gp21 crystal structure. The peptide B-cell epitopes were grafted onto the epsilon side chains of three lysyl residues on a template backbone construct consisting of the sequence acetyl-XGKGKGKGCONH2 (where X represents the tetanus toxoid promiscuous T cell epitope (TT) sequence 580-599). Leucine substitutions were introduced at the a and d positions of the CCR2T sequence to maximize helical character and stability as shown by circular dichroism and guanidinium hydrochloride studies. Serum from an HTLV-1-infected patient was able to recognize the selected epitopes by enzyme-linked immunosorbent assay (ELISA). Mice immunized with the wild-type sequence (WCCR2T) and the mutant sequence (CCR2T) elicited high antibody titers that were capable of recognizing the native protein as shown by flow cytometry and whole virus ELISA. Sera and purified antibodies from immunized mice were able to reduce the formation of syncytia induced by the envelope glycoprotein of HTLV-1, suggesting that antibodies directed against the coiled coil region of gp21 are capable of disrupting cell-cell fusion. Our results indicate that these peptides represent potential candidates for use in a peptide vaccine against HTLV-1.

The Kaposi sarcoma–associated herpesvirus (KSHV)–encoded latency-associated nuclear antigen (LANA) modulates viral and cellular gene expression, including interleukin 6 (IL-6), a growth factor for KSHV-associated diseases. LANA-driven IL-6 expression is dependent on the activator protein 1 (AP1) response element (RE) within the IL-6 promoter. We show that LANA activates the AP1 RE in a Jun-dependent fashion and that LANA enhances the transcriptional activity of a GAL4-Jun fusion protein. Coimmunoprecipitation studies documented a physical interaction between LANA and c-Jun in transiently transfected 293 cells as well as the KSHV-infected BCBL-1 primary effusion lymphoma (PEL) cell line. Taken together, these data indicate that LANA is a transcriptional coactivator of c-Jun. In addition, electrophoretic mobility shift assays demonstrated that LANA induces binding of a c-Jun-Fos heterodimer to the AP1 RE, but does not itself bind to the AP1 RE. RNA interference experiments confirmed that LANA activates the AP1 RE, stimulates binding of a c-Jun-Fos heterodimer to the AP1 RE, and induces expression of IL-6. These data indicate that LANA is a transcriptional coactivator of c-Jun, a function that may have implications for the pathogenesis of KSHV-associated diseases.

Cytotoxic T-lymphocytes are critical in the clearance of chronic viral infections such as HTLV-1. Peptide-based vaccines may have potential application in invoking antiviral CTL responses. In the development of vaccination strategies, it is becoming increasingly important to elicit a broad immune response against several epitopes simultaneously that may provide large population coverage. In the present study, we addressed this issue, namely the processing and presentation of multiple CTL epitopes simultaneously for the generation of multispecific CTL responses. We designed a novel multivalent peptide consisting of three HLA-A(*)0201 restricted CTL epitopes, with intervening double arginine residues in tandem. These epitopes were derived from the HTLV-1 regulatory protein Tax, which is an attractive target for vaccine development against HTLV-1. Arginine residues were included to provide cleavage sites for proteasomes, to generate the intended MHC Class I ligands. Proteasomal digestion studies and mass spectrometry analysis showed cleavage of the multivalent construct to generate the individual epitopes. Immunization of HLA-A(*)0201 transgenic mice with this construct efficiently elicited cellular responses to each intended epitope in vivo, further validating the applicability of this approach. These data may have potential in the development of immunotherapeutic strategies for the treatment of HTLV-1 disease and in the future design of multivalent subunit peptide vaccines.

In addition to reducing the analysis time, the direct examination of proteolytic digests by fast atom bombardment mass spectrometry (FABMS) greatly extends the information that is available from peptide mapping experiments. Mass spectral data are particularly useful for identifying post-translationally modified peptides. For example, the molecular weight of a disulfide-containing peptide may be used to locate the disulfide bond in the protein from which the peptide was derived. This paper describes a new procedure, which is useful for identifying disulfide-bonded peptides. Peptides are treated with performic acid to modify certain residues and thereby cause a characteristic change in the peptide molecular weight. This change in molecular weight is determined by FABMS and used to help identify peptides. Results for a series of small peptides demonstrate that Cys, Met, and Trp are the only residues that undergo a change in molecular weight under the conditions used here. Furthermore, these changes in molecular weight are diagnostic for each of the residues. Cysteinyl-containing peptides are of particular interest, because their identification is essential for locating disulfide bonds. The molecular weight of a peptide increases by 48 mu for each cysteinyl residue present. This approach is used to identify peptides that contain both cysteinyl and cystinyl residues in the peptic digest of bovine insulin. The method is extended to the analysis of a tryptic digest of cyanogen bromide-treated ribonuclease A. A computer-assisted analysis procedure is used to demonstrate the specifity with which peptide molecular weight is related to specific segments of the protein. These results demonstrate that the shift in peptide molecular weight, after the digest is treated with performic acid, leads to unique assignment of the six cysteinyl-containing peptides found in the digest.

Dandruff and seborrheic dermatitis (D/SD) are common hyperproliferative scalp disorders with a similar etiology. Both result, in part, from metabolic activity of Malassezia globosa and Malassezia restricta, commensal basidiomycete yeasts commonly found on human scalps. Current hypotheses about the mechanism of D/SD include Malassezia-induced fatty acid metabolism, particularly lipase-mediated breakdown of sebaceous lipids and release of irritating free fatty acids. We report that lipase activity was detected in four species of Malassezia, including M. globosa. We isolated lipase activity by washing M. globosa cells. The isolated lipase was active against diolein, but not triolein. In contrast, intact cells showed lipase activity against both substrates, suggesting the presence of at least another lipase. The diglyceride-hydrolyzing lipase was purified from the extract, and much of its sequence was determined by peptide sequencing. The corresponding lipase gene (LIP1) was cloned and sequenced. Confirmation that LIP1 encoded a functional lipase was obtained using a covalent lipase inhibitor. LIP1 was differentially expressed in vitro. Expression was detected on three out of five human scalps, as indicated by reverse transcription-PCR. This is the first step in a molecular description of lipid metabolism on the scalp, ultimately leading toward a test of its role in D/SD etiology.