C E Creutz

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Several cytosolic proteins bind to secretory granule membranes in a Ca2+-dependent manner and thus may be involved in the mediation of membrane interactions during exocytosis. One of these proteins, calpactin, is a tetramer consisting of two heavy chains of relative molecular mass (Mr) 36K (p36) and two light chains of 10K (p10). We report here that(More)
When isolated chromaffin granules were aggregated by synexin (a Ca2+-binding protein present in chromaffin and other secretory tissues) and then exposed to cis-unsaturated fatty acids at 37 degrees C, they fused together to form large vesicles. The fusion was monitored by phase and electron microscopy and by turbidity measurements on the granule suspension.(More)
The annexins are a group of homologous proteins that bind phospholipids in the presence of calcium. They may provide a major pathway for communication between cellular membranes and their cytoplasmic environment. Annexins have a characteristic "bivalent" activity in the sense that they can draw two membranes together when activated by calcium. This has led(More)
Using monoclonal antibodies specific for p60c-src we have detected high levels of this kinase in adrenal medullary chromaffin tissue and in highly purified chromaffin granule (secretory vesicle) membranes. An immune complex kinase assay was applied to fractions of adrenal medullary tissue resolved on sucrose density gradients. Thirty-seven per cent of the(More)
Chromobindin A is a multisubunit complex ATPase that binds to chromaffin granule membranes in a calcium-dependent manner and requires ATP for release from the membrane (Martin, W. H., and Creutz, C. E. (1987) J. Biol. Chem. 262, 2803-2810). Here we report that the seven previously characterized subunits of chromobindin A cross react with antisera specific(More)
Cultures of the nematode C. elegans were examined for the presence of calcium-dependent, phospholipid-binding proteins of the annexin class. A single protein of apparent mass on SDS-polyacrylamide gels of 32 kD was isolated from soluble extracts of nematode cultures on the basis of its ability to bind to phospholipids in a calcium-dependent manner. After(More)
Synaptotagmin I, an integral membrane protein of secretory vesicles, appears to have an essential role in calcium-triggered hormone and neurotransmitter release. The large cytoplasmic domain of synaptotagmin I has two C2 domains that are thought to mediate calcium and phospholipid binding. A recombinant protein (p65 1-5) comprised of the cytoplasmic domain(More)