Characterization of the fission yeast mcs2 cyclin and its associated protein kinase activity.
Characterization of the fission yeast mcs2 cyclin and its associated protein kinase activity.
复制标题
裂殖酵母 mcs2 细胞周期蛋白及其相关蛋白激酶活性的表征。
DOI：
10.1002/j.1460-2075.1993.tb05817.x
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Beach,D
中科院分区：
文献类型：
--
作者：
Molz,L;Beach,D
我们之前已经描述了mcs 2 - 75的分离，这是一种突变，作为cdc 2显性等位基因的等位基因特异性抑制因子获得。MCS 2被克隆并确定为必需基因，其产物与蛋白质的细胞周期蛋白家族共享同源性。与某些细胞周期蛋白（但不是所有细胞周期蛋白）的行为相反，mcs 2蛋白在整个细胞周期中的丰度和定位是恒定的。当髓鞘碱性蛋白（MBP）作为外源性底物提供时，可以检测到与mcs 2共沉淀的激酶活性。这种激酶活性在整个细胞周期中是恒定的。MCS 2似乎不与CDC 2蛋白激酶或抗原相关激酶相关。最后，一种称为csk 1（细胞周期蛋白抑制激酶）的蛋白激酶被分离出来作为mcs 2突变的高拷贝抑制因子。然而，CSK 1不是必需的，与MCS 2共沉淀的激酶活性水平在携带CSK 1无效等位基因的菌株中降低约3倍。因此，csk 1可能编码与mcs 2物理相关的蛋白激酶，或者可能作为mcs 2相关激酶的上游激活剂发挥作用。
We have previously described the isolation of mcs2‐75, a mutation obtained as an allele‐specific suppressor of a dominant allele of cdc2. mcs2 was cloned and determined to be an essential gene, the product of which shares homology with the cyclin family of proteins. In contrast to the behavior of some, but not all cyclins, the mcs2 protein is constant in its abundance and localization throughout the cell cycle. A kinase activity that co‐precipitates with mcs2 can be detected when myelin basic protein (MBP) is provided as an exogenous substrate. This kinase activity is constant throughout the cell cycle. mcs2 does not appear to associate with the cdc2 protein kinase or an antigenically related kinase. Finally, a protein kinase termed csk1 (cyclin suppressing kinase) was isolated as a high copy suppressor of an mcs2 mutation. csk1 is not essential, however, the level of kinase activity that co‐precipitates with mcs2 is reduced approximately 3‐fold in strains harboring a csk1 null allele. Therefore, csk1 may encode a protein kinase physically associated with mcs2 or alternatively may function as an upstream activator of the mcs2‐associated kinase.