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Structure, assembly, and secretion of octameric invertase.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 1987 Mar 25; Vol. 262 (9), pp. 4387-94. - Publication Year :
- 1987
-
Abstract
- Yeast invertase forms a homo-octamer of core glycosylated subunits during assembly in the lumen of the endoplasmic reticulum. This form has been purified from mutant cells (sec18) in which transport of secreted proteins from the endoplasmic reticulum is blocked. No heterologous protein subunits are found in the purified material. Analysis of invertase derived from wild type cells or from mutant cells blocked at subsequent stages in secretion demonstrates that invertase remains a homo-octamer throughout the pathway even though the extent of subunit glycosylation increases. Purified octameric invertase is dissociated into dimer units that reassociate in the presence of polyethylene glycol. Negatively stained preparations show the dissociated enzyme as individual spheres, whereas octameric invertase appears as four associated spheres. Assembly of the octamer in vitro and in vivo is facilitated by the presence of N-linked carbohydrate. Selective release of dimeric glycosylated invertase from intact yeast cells suggests that oligomerization helps retain the enzyme in the periplasmic space.
- Subjects :
- Acid Phosphatase metabolism
Cytoplasm enzymology
Cytoplasmic Granules enzymology
Endoplasmic Reticulum enzymology
Glycosylation
Golgi Apparatus enzymology
Macromolecular Substances
Microscopy, Electron
Molecular Weight
Mutation
Saccharomyces cerevisiae genetics
alpha-Galactosidase metabolism
beta-Fructofuranosidase
Glycoside Hydrolases metabolism
Protein Processing, Post-Translational
Saccharomyces cerevisiae enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 262
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 3031075