Tripp M L, Bouchard R A, Piñón R
Department of Biology, University of California, San Diego, La Jolla 92093.
Mol Microbiol. 1989 Oct;3(10):1319-27. doi: 10.1111/j.1365-2958.1989.tb00113.x.
The NSP1 gene in Saccharomyces cerevisiae has been identified by its ability, when expressed at high levels, to bypass the CDC25 requirement for growth. Sequence analysis of the cloned NSP1 locus suggests that the NSP1 product contains 269 amino acids and has a membrane-spanning domain at its carboxyl terminus. The NSP1 protein does not have sequence similarity to other known proteins, and is not related to the CDC25 protein, or to any of the previously described suppressors of CDC25 mutants. Phosphoprotein analysis of NSP1-suppressed cells indicates that the NSP1 product controls the phosphorylation of two 31 kD proteins whose phosphorylation and dephosphorylation are strongly correlated with cell-cycle arrest and proliferation, respectively, and suggests that the NSP1 product is an important downstream element of a CDC25-dependent, nutrient-responsive, phosphorylation pathway.
酿酒酵母中的NSP1基因已通过其高水平表达时绕过对CDC25生长需求的能力得以鉴定。对克隆的NSP1基因座的序列分析表明，NSP1产物包含269个氨基酸，并且在其羧基末端具有一个跨膜结构域。NSP1蛋白与其他已知蛋白没有序列相似性，与CDC25蛋白或之前描述的任何CDC25突变体的抑制因子均无关联。对NSP1抑制细胞的磷蛋白分析表明，NSP1产物控制着两种31 kD蛋白的磷酸化，这两种蛋白的磷酸化和去磷酸化分别与细胞周期停滞和增殖密切相关，这表明NSP1产物是CDC25依赖性、营养应答性磷酸化途径的一个重要下游元件。
