Li W, Han M, Guan K L
Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 USA.
Genes Dev. 2000 Apr 15;14(8):895-900.
Caenorhabditis elegans sur-8 encodes a positive regulator of Ras signaling. We investigated the mechanism by which the human Sur-8 homolog can positively regulate Ras-MAP kinase signaling in mammalian cells. Sur-8 expression enhances Ras- or EGF-induced Raf and ERK activation but has no effect on ERK activation induced by active Raf or MEK. Furthermore, Sur-8 expression does not increase AKT or JNK activation. Sur-8 interacts with Ras and Raf and is able to form a ternary complex with the two proteins. Thus, Sur-8 may function as a scaffold that enhances Ras-MAP kinase signal transduction by facilitating the interaction between Ras and Raf.
秀丽隐杆线虫的sur-8编码一种Ras信号通路的正向调节因子。我们研究了人类Sur-8同源物在哺乳动物细胞中正向调节Ras-MAP激酶信号通路的机制。Sur-8的表达增强了Ras或表皮生长因子（EGF）诱导的Raf和ERK激活，但对活性Raf或MEK诱导的ERK激活没有影响。此外，Sur-8的表达不会增加AKT或JNK的激活。Sur-8与Ras和Raf相互作用，并能够与这两种蛋白质形成三元复合物。因此，Sur-8可能作为一种支架，通过促进Ras和Raf之间的相互作用来增强Ras-MAP激酶信号转导。
