Yeast Rio1p is the founding member of a novel subfamily of protein serine kinases involved in the control of cell cycle progression
Yeast Rio1p is the founding member of a novel subfamily of protein serine kinases involved in the control of cell cycle progression
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DOI：
10.1046/j.1365-2958.2002.02881.x
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发表时间：
2002-04-01
影响因子：
3.6
通讯作者：
Bandlow, W
中科院分区：
文献类型：
--
作者：
Angermayr, M;Roidl, A;Bandlow, W
Rio 1 p是一种丝氨酸蛋白激酶，是一个新的丝氨酸蛋白激酶亚家族。它是高度保守的，从水母到人，只有远亲以前建立的蛋白激酶家族。然而，多个蛋白质序列比对的分析表明，那些在常规蛋白激酶中对结构或催化活性重要的氨基酸残基在Rio 1 p家族成员中的相应位置（对应于蛋白激酶的结构域I-XI）也是保守的。来自大肠杆菌的重组Rio 1 p和来自酵母的标记Rio 1 p在体外具有激酶活性，并且保守的且对于催化活性不可或缺的氨基酸残基（即ATP结合基序，催化中心）的突变消除活性。RIO 1在酵母中是必需的，在细胞周期进程中起作用。在RIO 1/Rio 1二倍体孢子形成后，RIO 1破坏的后代在1至3次细胞分裂后停止生长，并停滞为大的未出芽细胞或大的出芽细胞。失去Rio 1 p的细胞增大并停滞在G1期或有丝分裂期，主要是芽颈处的DNA和短纺锤体（携带弱等位基因的细胞中也可见的表型），表明Rio 1 p活性在细胞分裂周期中至少需要两个步骤：进入S期和退出有丝分裂。弱RIO 1等位基因导致质粒丢失增加。
Rio1p was identified as a protein serine kinase founding a novel subfamily. It is highly conserved from Archaea to man and only distantly related to previously established protein kinase families. Nevertheless, analysis of multiple protein sequence alignments shows that those amino acid residues that are important for either structure or catalytic activity in conventional protein kinases are also conserved in members of the Rio1p family at the respective positions (corresponding to domains I-XI of protein kinases). Recombinant Rio1p from Escherichia coli and tagged Rio1p from yeast has kinase activity in vitro , and mutation of amino acid residues that are conserved and indispensable for catalytic activity (i.e. ATP-binding motif, catalytic centre) abrogates activity. RIO1 is essential in yeast and plays a role in cell cycle progression. After sporulation of RIO1/rio1 diploids, RIO1 -disrupted progeny cease growth after one to three cell divisions and arrest as either large unbudded or large-budded cells. Cells deprived of Rio1p are enlarged and arrest either in G1 or in mitosis mainly with the DNA at the bud neck and short spindles (a phenotype also seen in cells carrying a weak allele), suggesting that Rio1p activity is required for at least at two steps during the cell division cycle: for entrance into S phase and for exit from mitosis. The weak RIO1 allele leads to increased plasmid loss.