Plasma membrane localization of the Yck2p yeast casein kinase 1 isoform requires the C-terminal extension and secretory pathway function
Plasma membrane localization of the Yck2p yeast casein kinase 1 isoform requires the C-terminal extension and secretory pathway function
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DOI：
10.1242/jcs.00203
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发表时间：
2002-12-15
影响因子：
4
通讯作者：
Robinson, LC
中科院分区：
文献类型：
--
作者：
Babu, P;Bryan, JD;Robinson, LC
酿酒酵母 Yck2 蛋白是酪蛋白激酶 I 蛋白激酶家族的质膜相关成员，与其同源物 Yck1p 是芽形态发生、胞质分裂、内吞作用和其他细胞过程所必需的。 Yckp 的膜定位对其功能至关重要，因为可溶性突变体不能提供足够的生物活性来维持正常生长。 Yck2p既没有预测的信号序列，也没有明显的跨膜结构域来实现其质膜定位，但具有可能被棕榈酰化的C端-Cys-Cys序列。我们在此证明 Yck2p 通过与经典分泌途径的囊泡中间体结合来靶向。缺乏 C 端 Cys 残基的 Yck2p 无法与任何膜结合，而用法呢基转移酶信号序列替换这些残基可以实现依赖于细胞膜的靶向和生物功能，这表明与早期分泌膜相互作用需要修饰，但靶向不需要特定的修饰。 185 个残基 C 端内的删除分析表明，最后 28 个残基对于膜缔合至关重要，并且需要上游的附加序列才能正确定位质膜。
The S. cerevisiae Yck2 protein is a plasma membrane associated member of the casein kinase I protein kinase family that, with its homolog Yck1p, is required for bud morphogenesis, cytokinesis, endocytosis and other cellular processes. Membrane localization of Yckp is critical for its function, since soluble mutants do not provide sufficient biological activity to sustain normal growth. Yck2p has neither a predicted signal sequence nor obvious transmembrane domain to achieve its plasma membrane localization, but has a C-terminal -Cys-Cys sequence that is likely to be palmitoylated. We demonstrate here that Yck2p is targeted through association with vesicular intermediates of the classical secretory pathway. Yck2p lacking C-terminal Cys residues fails to associate with any membrane, whereas substitution of these residues with a farnesyl transferase signal sequence allows see-dependent plasma membrane targeting and biological function, suggesting that modification is required for interaction with early secretory membranes but that targeting does not require a particular modification. Deletion analysis within the 185 residue C-terminus indicates that the final 28 residues are critical for membrane association, and additional sequences just upstream are required for proper plasma membrane targeting.