低分子量GTP结合蛋白rap1在大鼠腮腺质膜和分泌颗粒膜中的定位

Localization of a low Mr GTP-binding protein, rap1 protein, in plasma membranes and secretory granule membranes of rat parotid gland.

作者信息

Kameyama Y, Nagata K, Mizuno-Kamiya M, Yokota Y, Fujita A, Nozawa Y

机构信息

Department of Oral Biochemistry, Asahi University School of Dentistry, Gifu, Japan.

出版信息

Life Sci. 1994;55(3):213-9. doi: 10.1016/0024-3205(94)00882-5.

DOI:10.1016/0024-3205(94)00882-5

PMID:8007763

Abstract

Subcellular fractions were prepared from rat parotid gland by sequential centrifugation, Percoll gradient centrifugation and divalent-cation precipitation, and the localization of a low Mr GTP-binding protein, rap1 protein (rap1p) was analyzed by immunoblotting using a specific antibody. rap1p was found to be located in apical and basolateral plasma membranes, and secretory granule membranes in rat parotid gland. On the other hand, the beta gamma subunits of heterotrimeric Gt protein was localized in plasma membranes but not in granule membranes.

摘要

通过连续离心、Percoll梯度离心和二价阳离子沉淀从大鼠腮腺制备亚细胞组分，并用特异性抗体通过免疫印迹分析低分子量GTP结合蛋白rap1蛋白（rap1p）的定位。发现rap1p位于大鼠腮腺的顶端和基底外侧质膜以及分泌颗粒膜中。另一方面，异源三聚体Gt蛋白的βγ亚基定位于质膜而非颗粒膜中。