Perrin D, Söling H D
Abteilung Klinische Biochemie, Zentrum innere Medizin, Göttingen, Germany.
FEBS Lett. 1992 Oct 26;311(3):302-4. doi: 10.1016/0014-5793(92)81125-6.
Stimulation of secretion in chromaffin and parotid acinar cells is associated with dramatic rearrangements of the subplasmalemmal cytoskeleton, notably of fodrin and F-actin. It has been proposed that a proteolytic cleavage of fodrin resulting from an activation of the neutral calcium activated protease (calpain) could be responsible for these changes. Using an affinity-purified anti-alpha-fodrin antibody, several cleavage products of fodrin could clearly be detected following incubation of total cell homogenates from chromaffin and parotid acinar cells with purified calpain I. On the other hand, maximum stimulation of secretion of chromaffin cells by nicotine, and of parotid acinar cells by carbachol plus isoproterenol, was not associated with an increased appearance of cleavage products of fodrin. This result is not compatible with the 'proteolytic cleavage' hypothesis.
嗜铬细胞和腮腺腺泡细胞中分泌的刺激与质膜下细胞骨架的显著重排有关，尤其是血影蛋白和F-肌动蛋白。有人提出，中性钙激活蛋白酶（钙蛋白酶）激活导致的血影蛋白蛋白水解切割可能是这些变化的原因。使用亲和纯化的抗α-血影蛋白抗体，在用纯化的钙蛋白酶I孵育嗜铬细胞和腮腺腺泡细胞的全细胞匀浆后，可以清楚地检测到血影蛋白的几种切割产物。另一方面，尼古丁对嗜铬细胞分泌的最大刺激，以及卡巴胆碱加异丙肾上腺素对腮腺腺泡细胞分泌的最大刺激，与血影蛋白切割产物出现增加无关。这一结果与“蛋白水解切割”假说不相符。
