The SH3 domain of the S. cerevisiae Cdc25p binds adenylyl cyclase and facilitates Ras regulation of cAMP signalling.
The SH3 domain of the S. cerevisiae Cdc25p binds adenylyl cyclase and facilitates Ras regulation of cAMP signalling.
复制标题
酿酒酵母 Cdc25p 的 SH3 结构域结合腺苷酸环化酶并促进 Ras 对 cAMP 信号传导的调节。
DOI：
10.1016/s0898-6568(98)00044-8
复制
发表时间：
1999
影响因子：
4.8
通讯作者：
Field,J
中科院分区：
文献类型：
--
作者：
Mintzer,KA;Field,J
Cdc 25和Ras是芽殖酵母酿酒酵母中cAMP信号传导所需的两种蛋白质。Cdc 25是激活Ras的鸟嘌呤核苷酸交换蛋白。Ras反过来又激活腺苷酸环化酶。Cdc 25在N端附近具有Src同源性3（SH 3）结构域，在C端区域具有催化结构域。我们发现，在SH 3结构域的点突变减弱cAMP信号在葡萄糖喂养。此外，我们证明，通过使用重组腺苷酸环化酶和Cdc 25，Cdc 25的SH 3结构域可以直接结合腺苷酸环化酶。结合是特异性的，因为结合腺苷酸环化酶CAP/Srv 2的70，000 Mr亚基的Abp 1 p（肌动蛋白结合蛋白1）的SH 3结构域不能结合腺苷酸环化酶。Cdc 25-SH 3的结合位点定位于腺苷酸环化酶的C-末端催化区。最后，与Ras预孵育增强了SH 3结合的腺苷酸环化酶活性。这些研究表明，Cdc 25和腺苷酸环化酶之间的直接相互作用促进腺苷酸环化酶复合物的有效组装。
Cdc25 and Ras are two proteins required for cAMP signalling in the budding yeast Saccharomyces cerevisiae. Cdc25 is the guanine nucleotide exchange protein that activates Ras. Ras, in turn, activates adenylyl cyclase. Cdc25 has a Src homology 3 (SH3) domain near the N-terminus and a catalytic domain in the C-terminal region. We find that a point mutation in the SH3 domain attenuates cAMP signalling in response to glucose feeding. Furthermore, we demonstrate, by using recombinant adenylyl cyclase and Cdc25, that the SH3 domain of Cdc25 can bind directly to adenylyl cyclase. Binding was specific, because the SH3 domain of Abp1p (actin-binding protein 1), which binds the 70,000 Mrsubunit of adenylyl cyclase, CAP/Srv2, failed to bind adenylyl cyclase. A binding site for Cdc25-SH3 localised to the C-terminal catalytic region of adenylyl cyclase. Finally, pre-incubation with Ras enhanced the SH3-bound adenylyl cyclase activity. These studies suggest that a direct interaction between Cdc25 and adenylyl cyclase promotes efficient assembly of the adenylyl cyclase complex.