Suppression of microphthalmia transcriptional activity by its association with protein kinase C-interacting protein 1 in mast cells
Suppression of microphthalmia transcriptional activity by its association with protein kinase C-interacting protein 1 in mast cells
复制标题
DOI：
10.1074/jbc.274.48.34272
复制
发表时间：
1999-11-26
影响因子：
4.8
通讯作者：
Rivera, J
中科院分区：
文献类型：
--
作者：
Razin, E;Zhang, ZC;Rivera, J
小眼症（mi）是一种转录因子，在肥大细胞和黑素细胞的生长和功能调节中起主要作用。mi与其他蛋白的结合是mi介导的转录激活调控的关键步骤。我们在酵母双杂交筛选中发现了与mi特异性结合的蛋白激酶C相互作用蛋白1（PKCI）。从静止的大鼠嗜碱性白血病细胞或小鼠黑素细胞的mi的免疫沉淀导致PKCI的特异性免疫共沉淀。这种关联显着减少的参与肥大细胞的表面Fc ε RI或黑素细胞上的试剂盒受体的参与。因此，细胞活化导致mi从PKCI脱离。小眼症以前被证明可以激活小鼠肥大细胞蛋白酶6（mMCP-6）启动子。共转染mi与PKCI在NIH 3 T3成纤维细胞含有mMCP-6启动子-荧光素酶报告证明了高达94%的抑制mi介导的转录激活PKCI本身，虽然定位在细胞的胞质溶胶和细胞核中，没有已知的生理功能，并没有表现出转录活性。它在瞬时转染成纤维细胞系统中抑制mi转录活性的能力表明它可以在体内作为mi诱导的转录激活的负调节因子发挥作用。
Microphthalmia (mi) is a transcription factor that plays a major role in the regulation of growth and function in mast cells and melanocytes. Association of mi with other proteins is a critical step in the regulation of mi-mediated transcriptional activation We found protein kinase C-interacting protein 1 (PKCI) specifically associated with mi in yeast two-hybrid screening. Immunoprecipitation of mi from quiescent rat basophilic leukemic cells or mouse melanocytes resulted in the specific co-immunoprecipitation of PKCI. This association was significantly reduced on engagement of the surface Fc epsilon RI of mast cells or engagement of the Kit receptor on melanocytes. Hence, cell activation caused disengagement of mi from PKCI. Microphthalmia was previously shown to activate the mouse mast cell protease 6 (mMCP-6) promoter. Cotransfection of mi with PKCI in NIH 3T3 fibroblasts containing an mMCP-6 promoter-luciferase reporter demonstrated an up to 94% inhibition of mi-mediated transcriptional activation PKCI by itself, although localized in the cytosol and nucleus of the cells, has no known physiological function and did not demonstrate transcriptional activity. Its ability to suppres mi transcriptional activity in the transient transfected fibroblast system suggests that it can function in vivo as a negative regulator of mi-induced transcriptional activation.