biostudies-literatureUnknown13(9)Way GWellcome TrustAfter permeabilization with the pore-forming toxin streptolysin-O mast cells can be triggered to secrete by addition of both calcium and a GTP analogue. If stimulation is delayed after permeabilization, there is a progressive decrease in the extent of secretion upon stimulation, eventually leading to a complete loss of the secretory response. This loss of secretory response can be retarded by the addition of cytosol from other secretory tissues, demonstrating that the response is dependent on a number of cytosolic proteins. We have used this as the basis of a bioassay to purify Secernin 1, a novel 50-kDa cytosolic protein that appears to be involved in the regulation of exocytosis from peritoneal mast cells. Secernin 1 increases both the extent of secretion and increases the sensitivity ofMolecular biology of the cell3344-54https://www.ebi.ac.uk/biostudies/studies/S-EPMC124164biostudies-literaturePurification and identification of secernin, a novel cytosolic protein that regulates exocytosis in mast cells.PMC124164Way GO'Sullivan AJSmythe CMorrice NfalsePurification and identification of secernin, a novel cytosolic protein that regulates exocytosis in mast cells.After permeabilization with the pore-forming toxin streptolysin-O mast cells can be triggered to secrete by addition of both calcium and a GTP analogue. If stimulation is delayed after permeabilization, there is a progressive decrease in the extent of secretion upon stimulation, eventually leading to a complete loss of the secretory response. This loss of secretory response can be retarded by the addition of cytosol from other secretory tissues, demonstrating that the response is dependent on a number of cytosolic proteins. We have used this as the basis of a bioassay to purify Secernin 1, a novel 50-kDa cytosolic protein that appears to be involved in the regulation of exocytosis from peritoneal mast cells. Secernin 1 increases both the extent of secretion and increases the sensitivity of2002-01-01T00:00:00Z2002 Sep2025-05-31T23:21:37.975Z2019-03-27T00:17:13ZS-EPMC1241641222113810.1091/mbc.e01-10-0094