Yarden O, Plamann M, Ebbole D J, Yanofsky C
Department of Biological Sciences, Stanford University, CA 94305.
EMBO J. 1992 Jun;11(6):2159-66. doi: 10.1002/j.1460-2075.1992.tb05275.x.
Neurospora crassa is a filamentous fungus that grows on semisolid media by forming spreading colonies. Mutations at several loci prevent this spreading growth. cot-1 is a temperature sensitive mutant of N.crassa that exhibits restricted colonial growth. At temperatures above 32 degrees C colonies are compact while at lower temperatures growth is indistinguishable from that of the wild type. Restricted colonial growth is due to a defect in hyphal tip elongation and a concomitant increase in hyphal branching. We have isolated a genomic cosmid clone containing the wild type allele of cot-1 by complementation. Sequence analyses suggested that cot-1 encodes a member of the cAMP-dependent protein kinase family. Strains in which we disrupted cot-1 are viable but display restricted colonial growth. Duplication, by ectopic integration of a promoter-containing fragment which includes the first one-third (209 codons) of the structural gene, unexpectedly resulted in restricted colonial growth. Our results suggest that an active COT1 kinase is required for one or more events essential for hyphal elongation.
粗糙脉孢菌是一种丝状真菌，它通过形成扩散菌落生长在半固体培养基上。几个位点的突变会阻止这种扩散生长。cot-1是粗糙脉孢菌的一个温度敏感突变体，表现出受限的菌落生长。在32摄氏度以上的温度下，菌落紧凑，而在较低温度下，生长与野生型无明显差异。受限的菌落生长是由于菌丝尖端伸长缺陷和菌丝分支同时增加所致。我们通过互补分离出了一个包含cot-1野生型等位基因的基因组黏粒克隆。序列分析表明，cot-1编码一种cAMP依赖性蛋白激酶家族成员。我们破坏了cot-1的菌株是存活的，但表现出受限的菌落生长。通过异位整合包含结构基因前三分之一（209个密码子）的含启动子片段进行复制，意外地导致了受限的菌落生长。我们的结果表明，活性COT1激酶对于菌丝伸长所必需的一个或多个事件是必需的。
