CAK1 promotes meiosis and spore formation in Saccharomyces cerevisiae in a CDC28-independent fashion.
CAK1 promotes meiosis and spore formation in Saccharomyces cerevisiae in a CDC28-independent fashion.
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CAK1 以不依赖于 CDC28 的方式促进酿酒酵母的减数分裂和孢子形成。
DOI：
10.1128/mcb.22.1.57-68.2002
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发表时间：
2002
影响因子：
5.3
通讯作者：
Winter,Edward
中科院分区：
文献类型：
--
作者：
Schaber,Michael;Lindgren,Anne;Schindler,Karen;Bungard,David;Kaldis,Philipp;Winter,Edward
CAK 1编码酵母中的一种蛋白激酶，其唯一的有丝分裂作用是通过其激活环中的苏氨酸-169磷酸化激活Cdc 28 p细胞周期蛋白依赖性激酶; SMK 1编码孢子形成特异性的丝裂原激活蛋白（MAP）。一种调节孢子壁组装减数分裂后事件所需的激酶同源物。CAK 1以前被鉴定为一个弱化smk 1突变体的多拷贝抑制因子，并被证明是孢子壁组装所需的材料。在这里，我们表明，Smk 1 p，像其他MAP激酶，磷酸化在其激活环和Smk 1 p不激活acak 1错义突变体。携带CDC 28超活化等位基因的菌株是CAK 1独立的，缺乏苏氨酸-169仍然需要CAK 1激活Smk 1 p。这些数据表明，Cak 1 p的Smk 1 p的上游功能激活Cdc 28 p以外的蛋白激酶。我们还发现缺乏CAK 1的突变体在减数分裂发育的早期被阻断，因为它们在减数分裂前DNA合成中表现出实质性的延迟和孢子形成特异性基因（包括IME 1）表达的缺陷。与Smk 1 p途径中的减数分裂后作用一样，Cak 1 p在减数分裂早期的作用不依赖于CDC 28。这些数据表明，Cak 1 p通过多个蛋白激酶靶点激活减数分裂发育中的多个步骤。
CAK1encodes a protein kinase inSaccharomyces cerevisiaewhose sole essential mitotic role is to activate the Cdc28p cyclin-dependent kinase by phosphorylation of threonine-169 in its activation loop.SMK1encodes a sporulation-specific mitogen-activated protein (MAP) kinase homolog that is required to regulate the postmeiotic events of spore wall assembly.CAK1was previously identified as a multicopy suppressor of a weakenedsmk1mutant and shown to be required for spore wall assembly. Here we show that Smk1p, like other MAP kinases, is phosphorylated in its activation loop and that Smk1p is not activated in acak1missense mutant. Strains harboring a hyperactivated allele ofCDC28that isCAK1independent and that lacks threonine-169 still requireCAK1to activate Smk1p. The data indicate that Cak1p functions upstream of Smk1p by activating a protein kinase other than Cdc28p. We also found that mutants lackingCAK1are blocked early in meiotic development, as they show substantial delays in premeiotic DNA synthesis and defects in the expression of sporulation-specific genes, includingIME1. The early meiotic role of Cak1p, like the postmeiotic role in the Smk1p pathway, isCDC28independent. The data indicate that Cak1p activates multiple steps in meiotic development through multiple protein kinase targets.