6a68

Structural highlights

Function

[CAPS1_RAT] Calcium-binding protein involved in exocytosis of vesicles filled with neurotransmitters and neuropeptides. Probably acts upstream of fusion in the biogenesis or maintenance of mature secretory vesicles. Regulates catecholamine loading of DCVs. May specifically mediate the Ca(2+)-dependent exocytosis of large dense-core vesicles (DCVs) and other dense-core vesicles by acting as a PtdIns(4,5)P2-binding protein that acts at prefusion step following ATP-dependent priming and participates in DCVs-membrane fusion. However, it may also participate in small clear synaptic vesicles (SVs) exocytosis and it is unclear whether its function is related to Ca(2+) triggering.^{[1] [2] [3] [4] [5] [6]}

References

1. ↑ Rupnik M, Kreft M, Sikdar SK, Grilc S, Romih R, Zupancic G, Martin TF, Zorec R. Rapid regulated dense-core vesicle exocytosis requires the CAPS protein. Proc Natl Acad Sci U S A. 2000 May 9;97(10):5627-32. PMID:10792045 doi:http://dx.doi.org/10.1073/pnas.090359097
2. ↑ Walent JH, Porter BW, Martin TF. A novel 145 kd brain cytosolic protein reconstitutes Ca(2+)-regulated secretion in permeable neuroendocrine cells. Cell. 1992 Sep 4;70(5):765-75. PMID:1516133
3. ↑ Grishanin RN, Kowalchyk JA, Klenchin VA, Ann K, Earles CA, Chapman ER, Gerona RR, Martin TF. CAPS acts at a prefusion step in dense-core vesicle exocytosis as a PIP2 binding protein. Neuron. 2004 Aug 19;43(4):551-62. PMID:15312653 doi:http://dx.doi.org/10.1016/j.neuron.2004.07.028
4. ↑ Martin TF, Kowalchyk JA. Docked secretory vesicles undergo Ca2+-activated exocytosis in a cell-free system. J Biol Chem. 1997 May 30;272(22):14447-53. PMID:9162085
5. ↑ Berwin B, Floor E, Martin TF. CAPS (mammalian UNC-31) protein localizes to membranes involved in dense-core vesicle exocytosis. Neuron. 1998 Jul;21(1):137-45. PMID:9697858
6. ↑ Tandon A, Bannykh S, Kowalchyk JA, Banerjee A, Martin TF, Balch WE. Differential regulation of exocytosis by calcium and CAPS in semi-intact synaptosomes. Neuron. 1998 Jul;21(1):147-54. PMID:9697859