ACTIVITY OF THE YEAST MAP KINASE HOMOLOG SLT2 IS CRITICALLY REQUIRED FOR CELL INTEGRITY AT 37-DEGREES-C
ACTIVITY OF THE YEAST MAP KINASE HOMOLOG SLT2 IS CRITICALLY REQUIRED FOR CELL INTEGRITY AT 37-DEGREES-C
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DOI：
10.1007/bf00280215
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发表时间：
1993-10-01
期刊：
影响因子：
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通讯作者：
NOMBELA, C
中科院分区：
文献类型：
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作者：
MARTIN, H;ARROYO, J;NOMBELA, C
酿酒酵母的SLT 2基因编码MAP（丝裂原活化）蛋白激酶的同源物，该基因的缺失导致在37 ℃下生长的细胞中的自溶致死表型。该基因编码蛋白激酶的特征结构域，其包括位于富含甘氨酸的簇的19个残基的赖氨酸（在位置54处），该簇被认为是推定的ATP结合位点。通过定点突变产生的三个突变体等位基因，即E54（谷氨酸）、R54（精氨酸）和F54（苯丙氨酸），测试其与slt 2突变体互补的能力。所有三种都未能补充自溶表型，并且不能恢复细胞的生长和活力。通过slt 2-F54的置换获得的菌株也表现为温敏自溶突变体。通过免疫沉淀与多克隆抗体提出了针对在大肠杆菌中表达的Slt 2蛋白，这是可能的，以确认赖氨酸-54残基的改变并不影响蛋白质的稳定性，从而使我们能够得出结论，Slt 2蛋白激酶的活性是至关重要的生长和形态发生的S。酿酒酵母在37摄氏度。突变体细胞群的显著部分在24 ℃裂解，并且细胞显示出由细胞壁区域中的典型凹陷组成的表面的特征性改变。在37 ℃时，细胞表面明显紊乱。
Deletion of the SLT2 gene of Saccharomyces cerevisiae, which codes for a homologue of MAP (mitogen-activated) protein kinases, causes an autolytic lethal phenotype in cells grown at 37-degrees-C. The gene encodes domains characteristic of protein kinases, which include a lysine (at position 54) that lies 19 residues from a glycine-rich cluster, considered to be the putative ATP binding site. The ability of three mutant alleles of SLT2 generated by site-directed mutagenesis, namely E54 (glutamic acid), R54 (arginine) and F54 (phenylalanine), to complement slt2 mutants was tested. All three failed to complement the autolytic phenotype and were unable to restore growth and viability of cells. A strain obtained by transplacement of slt2-F54 also behaved as a thermosensitive autolytic mutant. By immunoprecipitation with polyclonal antibodies raised against Slt2 protein expressed in Escherichia coli, it was possible to confirm that alteration of the lysine-54 residue did not affect the stability of the protein, thus allowing us to conclude that activity of the Slt2 protein kinase is critically required for growth and morphogenesis of S. cerevisiae at 37-degrees-C. A significant fraction of the mutant cell population lysed at 24-degrees-C and the cells displayed a characteristic alteration of the surface consisting of a typical depression in an area of the cell wall. At 37-degrees-C, the cell surface was clearly disorganized.