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Calcium‐dependent secretory vesicle‐binding and lipid‐binding proteins of Saccharomyces cerevisiase
Author(s) -
Creutz Carl E.,
Snyder Sandara L.,
Kambouris Nicholas G.
Publication year - 1991
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.320070305
Subject(s) - biology , saccharomyces cerevisiae , biochemistry , yeast , calcium , cytosol , membrane protein , calcium binding protein , secretory protein , secretion , membrane , enzyme , chemistry , organic chemistry
Yeast ( Saccharomyces cerevisiae ) cytosol was examined for the presence of calcium‐dependent membrane‐ or lipidbinding proteins that might paly fundamental roles in membrane‐associated phenomena in stimulated cells. A complex group of proteins was isolated from late log phase cultures of yeast strain YP3 on the basis of calcium‐dependent association with yeast secretory vesicles isolated from the temperature‐sensitive sec6 ‐ 4 secretory mutant. The masses of the major proteins in this group were 32, 35, 47, 51, 55, 60, and 120 kDa. A similar group of proteins was isolated by calcium‐dependent association with bovine brain lipids enriched in the predominant acidic phospholipids of the yeast secretory vesicles. The 47 kDa protein was highly purified when commerical yeast cake was used as the source of yeast cytosol. The 32 kDa and 60 kDa proteins were demonstrated to reassociate with lipids at calcium concentrations of 100 μ M or higher, while no association was promoted by 2 m M ‐magnesium. The 47 kDa protein could be removed from lipids by reducing the calcium concentration to between 1 and 32 μ M . The sequences of peptides isolated from digests of several of these proteins indicate that they are novel proteins but are insufficient to judge the possible homology of these proteins with mammalian membrane‐binding proteins. The sequence data may be adequeate to permit isolation and modification of the corresponding genes in order to assess the possible funtion of this class of proteins in stimulated cells.