Snell V, Nurse P
ICRF Cell Cycle Laboratory, Imperial Cancer Research Fund, London, UK.
EMBO J. 1994 May 1;13(9):2066-74. doi: 10.1002/j.1460-2075.1994.tb06481.x.
We have initiated a study to identify genes regulating cell morphogenesis in the fission yeast Schizosaccharomyces pombe. Five genes have been identified, orb1-orb5, whose mutation gives rise to spherical cells, indicative of an inability to polarize growth. Two further genes have been identified, tea1 and ban1, whose mutant alleles have disturbed patterns of tip growth, leading to T-shaped and curved cells. In fission yeast, sites of cell wall deposition are defined by actin localization, with actin distributions and therefore growth patterns undergoing cell cycle stage-specific reorganization. Studies of double mutants constructed between orb5-19 and various cdc mutants blocked before and after cell division show that orb5 is required for the re-establishment of polar growth following cytokinesis. This indicates that the mutant allele orb5-19 is defective in the reinitiation of polarized growth, even though actin reorganization to the cell tips occurs normally. orb5 encodes a fission yeast homologue of casein kinase II alpha. We propose that this kinase plays a role in the translation of cell polarity into polarized growth, but not in the establishment of polarity itself.
我们已经启动了一项研究，以鉴定调控裂殖酵母粟酒裂殖酵母细胞形态发生的基因。已经鉴定出五个基因，即orb1-orb5，其突变会产生球形细胞，这表明无法进行极性生长。还鉴定出另外两个基因，tea1和ban1，其突变等位基因扰乱了顶端生长模式，导致形成T形和弯曲细胞。在裂殖酵母中，细胞壁沉积位点由肌动蛋白定位确定，肌动蛋白分布以及因此的生长模式会经历细胞周期阶段特异性的重组。对在orb5-19与细胞分裂前后被阻断的各种cdc突变体之间构建的双突变体的研究表明，orb5是胞质分裂后重新建立极性生长所必需的。这表明突变等位基因orb5-19在极化生长的重新启动中存在缺陷，尽管肌动蛋白向细胞顶端的重组正常发生。orb5编码酪蛋白激酶IIα的裂殖酵母同源物。我们提出，这种激酶在将细胞极性转化为极化生长中起作用，但在极性本身的确立中不起作用。
