ASSOCIATION OF THE GTP-BINDING PROTEIN-RAB3A WITH BOVINE ADRENAL CHROMAFFIN GRANULES
ASSOCIATION OF THE GTP-BINDING PROTEIN-RAB3A WITH BOVINE ADRENAL CHROMAFFIN GRANULES
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DOI：
10.1073/pnas.87.15.5692
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发表时间：
1990-08-01
影响因子：
11.1
通讯作者：
SCHERMAN, D
中科院分区：
文献类型：
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作者：
DARCHEN, F;ZAHRAOUI, A;SCHERMAN, D
Rab 3A蛋白属于存在于真核细胞中的小GTP结合蛋白的大家族，并且与Ras蛋白（ras原癌基因的产物）共享氨基酸同一性。Rab 3A特异性定位于神经和内分泌组织，被怀疑在分泌中起关键作用。用多克隆抗体研究了其在牛肾上腺中的定位。Rab 3A在肾上腺髓质中表达，在肾上腺皮质中未见表达。在培养的肾上腺髓质细胞中，Rab 3A在分泌儿茶酚胺的嗜铬细胞中特异性表达。亚细胞分级分离表明Rab 3A是约30%的cysteine，颗粒Rab 3A与嗜铬颗粒膜（儿茶酚胺储存细胞器）和第二个隔室可能是质膜。Rab 3A在嗜铬颗粒膜上的定位通过用抗多巴胺β-受体抗体的免疫吸附来证实。羟化酶Rab 3A没有从该膜中提取的NaCl或KBr，但部分提取的尿素和完全溶解的Triton X-100，这表明无论是与内在的蛋白质或膜协会通过脂肪酸酰化的相互作用。这项研究表明，Rab 3A，这也可能是位于其他分泌囊泡含有非特征性的小GTP结合蛋白，参与其生物合成或在调节分泌过程。
The Rab3A protein belongs to a large family of small GTP-binding proteins that are present in eukaryotic cells and that share amino acid identities with the Ras proteins (products of the ras protooncogenes). Rab3A, which is specifically located in nervous and endocrine tissues, is suspected to play a key role in secretion. Its localization was investigated in bovine adrenal gland by using a polyclonal antibody. Rab3A was detected in adrenal medulla but not in adrenal cortex. In cultured adrenal medulla cells, Rab3A was specifically expressed in the catecholamine-secreting chromaffin cells. Subcellular fractionation suggested that Rab3A is about 30% cystolic and that particulate Rab3A is associated with the membrane of chromaffin granules (the catecholamine storage organelles) and with a second compartment likely to be the plasma membrane. The Rab3A localization on chromaffin granule membranes was confirmed by immunoadsorption with an antibody agianst dopamine .beta.-hydroxylase. Rab3A was not extracted from this membrane by NaCl or KBr but was partially extracted by urea and totally solubilized by Triton X-100, suggesting either an interaction with an intrinsic protein or a membrane association through fatty acid acylation. This study suggests that Rab3A, which may also be located on other secretory vesicles containing noncharacterized small GTP-binding proteins, is involved in their biogenesis or in the regulated secretion process.