Regulated phosphorylation of secretory granule membrane proteins of the rat parotid gland.
Regulated phosphorylation of secretory granule membrane proteins of the rat parotid gland.
复制标题
调节大鼠腮腺分泌颗粒膜蛋白的磷酸化。
DOI：
10.1152/ajpgi.1990.259.1.g70
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Gorelick,FS
中科院分区：
文献类型：
--
作者：
Marino,CR;Castle,JD;Gorelick,FS
An antiserum raised against purified rat parotid secretory granule membrane proteins has been used to identify organelle-specific protein phosphorylation events following stimulation of intact cells from the rat parotid gland. After lobules were prelabeled with [32P]orthophosphate and exposed to secretagogues, phosphoproteins were immunoprecipitated with the granule membrane protein antiserum, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and visualized by autoradiography. Parallel studies of stimulated amylase release were performed. Isoproterenol treatment of parotid lobules resulted in an increase in the phosphate content of immunoprecipitable 60- and 72-kDa proteins that correlated with amylase release in a time-dependent manner. Forskolin addition mimicked these effects, but only the isoproterenol effects were reversed by propranolol treatment. To confirm the specificity of the antiserum to the secretory granule membrane fraction, subcellular isolation techniques were employed following in situ phosphorylation. The 60- and 72-kDa phosphoproteins were immunoprecipitated from both a particulate fraction and a purified secretory granule fraction. Furthermore, the extraction properties of both species suggest that they are integral membrane proteins. These findings support the possibility that stimulus-regulated secretion may involve phosphorylation of integral membrane proteins of the exocrine secretory granule.
