SIPA1（signal-induced proliferation-associated 1），癌症关联基因，基因ID：6494，该基因的产物是一种丝裂原诱导的gtpase激活蛋白（gap）。它对ras相关的调节蛋白rap1和rap2表现出特异的gap活性，但对ran或其他小gtpase则没有。当异常或过早表达时，这种蛋白也可能阻碍有丝分裂原诱导的细胞周期进程。它局限于核周区迄今为止，已经对编码相同亚型的两个交替拼接变体进行了表征。[由RefSeq提供，2008年7月]The product of this gene is a mitogen induced GTPase activating protein (GAP). It exhibits a specific GAP activity for Ras-related regulatory proteins Rap1 and Rap2， but not for Ran or other small GTPases. This protein may also hamper mitogen-induced cell cycle progression when abnormally or prematurely expressed. It is localized to the perinuclear region. Two alternatively spliced variants encoding the same isoform have been characterized to date. [provided by RefSeq， Jul 2008]。