Piletz J E, Wang G, Zhu H
Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
Ann N Y Acad Sci. 2003 Dec;1009:392-9. doi: 10.1196/annals.1304.053.
IRAS transfection into Chinese hamster ovary (CHO) or pheochromocytoma (PC-12) cell lines leads to the appearance of nonadrenergic binding sites for radiolabeled-clonidine. Nischarin is the mouse homologue of IRAS. IRAS seems to be a cytosolic protein that is anchored to the intracellular side of plasma membranes by a POX domain. Previous studies of IRAS-transfected HEK293 cells, and Nischarin-transfected 3T3 cells have shown this protein can intrinsically mediate cell growth and differentiation independent of imidazoline drugs through binding to insulin receptor substrates (HEK293 cells) and fibronectin receptors (3T3 cells). Herein, a growth-arrested PC-12 cell line stably transfected with IRAS is shown to express lower basal and nerve growth factor-stimulated levels of the activated form of extracellular receptor kinase than found in a vector-only transfected control cell line treated similarly. These findings suggest that IRAS is a membrane-associated mediator of receptor signaling.
将IRAS转染至中国仓鼠卵巢（CHO）或嗜铬细胞瘤（PC - 12）细胞系中，会导致出现放射性标记可乐定的非肾上腺素能结合位点。Nischarin是IRAS的小鼠同源物。IRAS似乎是一种胞质蛋白，通过一个POX结构域锚定在质膜的胞内侧。先前对IRAS转染的HEK293细胞以及Nischarin转染的3T3细胞的研究表明，该蛋白可通过与胰岛素受体底物（HEK293细胞）和纤连蛋白受体（3T3细胞）结合，独立于咪唑啉药物内在地介导细胞生长和分化。在此，与同样处理的仅转染载体的对照细胞系相比，稳定转染IRAS的生长停滞PC - 12细胞系显示出较低的基础水平以及神经生长因子刺激下的细胞外受体激酶活化形式水平。这些发现表明IRAS是受体信号传导的膜相关介质。
