A protein factor extracted from murine brains confers physiological Ca2+ sensitivity to exocytosis in sea urchin eggs

FEBS Letters

Sasaki, Hajime¹ 

[1] Bio-Science Laboratory Inc. and DRBC, 5-34-5 Shironishi, Yamagata 990, Japan

关键词: Exocytosis;    Sea urchin egg;    Brain;    Calcium;    Protein;   

DOI  :  10.1016/0014-5793(92)80620-V

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Exocytosis in sea urchin eggs can be reconstituted in vitro using the cell ghosts (the isolated cortices). When the isolated cortices were handled in the medium primarily composed of non-chaotropic ions, exocytosis can be induced by a micromolar level of Ca²⁺. However, when the cortices are exposed to chaotropic anions such as Cl⁻, it is induced only at higher Ca²⁺ concentrations of 10⁻⁵ to 10⁻⁴ M, due to the chaotropic anionic effect, by which a specific protein(s) is dissociated from the cortex. The dissociated protein can be added back to the cortex to restore the original Ca²⁺ sensitivity [(1984) Dev. Biol. 101, 125–135]. A protein which has the similar effect on the isolated cortex was also found in the extract of murine brain. This protein was neither calmodulin, a G-protein or a kinase. The data suggest the general regulatory mechanism of the Ca²⁺ sensitivity of exocytosis by a protein factor widely distributed among cells.

【 授权许可】

Unknown