YEAST NUM1P ASSOCIATES WITH THE MOTHER CELL CORTEX DURING S/G2 PHASE AND AFFECTS MICROTUBULAR FUNCTIONS
YEAST NUM1P ASSOCIATES WITH THE MOTHER CELL CORTEX DURING S/G2 PHASE AND AFFECTS MICROTUBULAR FUNCTIONS
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DOI：
10.1083/jcb.131.4.1003
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发表时间：
1995-11-01
影响因子：
7.8
通讯作者：
KUNTZEL, H
中科院分区：
文献类型：
--
作者：
FARKASOVSKY, M;KUNTZEL, H
NUM 1基因参与酿酒酵母细胞核迁移的调控。NUM 1 mRNA的表达在细胞周期中波动，在S/G2期达到最大值，翻译产物Num 1 p主要在S期、G2期和有丝分裂期与母细胞皮层结合。NUM 1缺陷的大芽细胞中的核纺锤体通常不能沿沿着母/芽轴排列，而异常伸长的星形微管从两个纺锤体极体发出。num 1无效突变赋予冷敏感性α-微管蛋白突变体tub 1 -1温度敏感性，并显示与β-微管蛋白突变体等位基因tub 2 -402、tub 2 -403、tub 2 -404和tub 2 -405的合成致死性。缺失图谱已经确定了三个功能重要的Num 1 p区域：一个潜在的EF手Ca 2+结合位点，一组潜在的磷酸化位点和一个pleckstrin同源结构域，后者似乎参与将Num 1 p靶向母细胞皮层。我们的数据表明，周期性表达的NUM 1基因产物通过影响星形微管功能来控制核迁移。
The NUM1 gene is involved in the control of nuclear migration in Saccharomyces cerevisiae, The content of NUM1 mRNA fluctuates during the cell cycle, reaching a maximum at S/G2 phase, and the translation product Num1p associates with the cortex of mother cells mainly during S, G2, and mitosis, as seen by indirect immunofluorescence. The nuclear spindle in NUM1-deficient large-budded cells often fails to align along the mother/bud axis, while abnormally elongated astral microtubules emanate from both spindle pole bodies. A num1 null mutation confers temperature sensitivity to the cold-sensitive alpha-tubulin mutant tub1-1, and shows synthetic lethality with the beta-tubulin mutant alleles tub2-402, tub2-403, tub2-404, and tub2-405. Deletion mapping has defined three functionally important Num1p regions: a potential EF hand Ca2+ binding site, a cluster of potential phosphorylation sites and a pleckstrin homology domain, The latter domain appears to be involved in targeting Num1p to the mother cell cortex. Our data suggest that the periodically expressed NUM1 gene product controls nuclear migration by affecting astral microtubule functions.