KAR3, A KINESIN-RELATED GENE REQUIRED FOR YEAST NUCLEAR-FUSION
KAR3, A KINESIN-RELATED GENE REQUIRED FOR YEAST NUCLEAR-FUSION
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DOI：
10.1016/0092-8674(90)90351-e
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发表时间：
1990-03-23
期刊：
影响因子：
64.5
通讯作者：
ROSE, MD
中科院分区：
文献类型：
--
作者：
MELUH, PB;ROSE, MD
KAR 3基因对于酵母在交配过程中的核融合是必需的，并且其表达由α诱导。因子预测的KAR 3蛋白质序列含有两个由α-β-CD分隔的球状结构域。螺旋状盘绕线圈。其羧基端结构域与果蝇驱动蛋白重链的氨基端机械化学结构域同源。假定的ATP结合位点的突变产生核融合的显性“毒物”。该突变蛋白显示出增强的微管协会在体内，作为一个驱动蛋白样蛋白在僵硬的结合状态的预测。本地化的杂合蛋白质的细胞质微管在shmoos表明，氨基末端结构域也包含微管协会的决定因素。因此，KAR 3是驱动蛋白样蛋白的较大家族的成员，其特征在于存在拴系到不同蛋白质结合结构域的机械化学结构域。kar 3突变体的表型表明，该蛋白质介导的微管滑动在核融合和可能的有丝分裂。
The KAR3 gene is essential for yeast nuclear fusion during mating, and its expression is strongly induced by .alpha. factor. The predicted KAR3 protein sequence contains two globular domains separated by an .alpha.-helical coiled coil. The carboxy-terminal domain is homologous to the amino-terminal mechanochemical domain of Drosophila kinesin heavy chain. Mutation of the putative ATP binding site produces a dominant "poison" of nuclear fusion. The mutant protein shows enhanced microtubule association in vivo, as predicted for a kinesin-like protein in a state of rigor binding. Localization of hybrid proteins to cytoplasmic microtubules in shmoos indicates that the amino-terminal domain also contains determinants for microtubule association. Thus, KAR3 is a member of a larger family of kinesin-like proteins characterized by the presence of the mechanochemical domain tethered to different protein binding domains. The phenotypes of kar3 mutants suggest that the protein mediates microtubule sliding during nuclear fusion and possibly mitosis.