Kormanec J, Schaaff-Gerstenschläger I, Zimmermann F K, Perecko D, Küntzel H
Max-Planck-Institut für experimentelle Medizin, Abteilung Chemie, Göttingen, FRG.
Mol Gen Genet. 1991 Nov;230(1-2):277-87. doi: 10.1007/BF00290678.
We have isolated a novel gene (NUM1) with unusual internal periodicity. The NUM1 gene encodes a 313 kDa protein with a potential Ca2+ binding site and a central domain containing 12 almost identical tandem repeats of a 64 amino acid polypeptide. num1-disrupted strains grow normally, but contain many budded cells with two nuclei in the mother cell instead of a single nucleus at the bud neck, while all unbudded cells are uninucleate. This indicates that most G2 nuclei divide in the mother before migrating to the neck, followed by the migration of one of the two daughter nuclei into the bud. Furthermore, haploid num1 strains tend to diploidize during mitosis, and homozygous num1 diploid or tetraploid cells sporulate to form many budded asci with up to eight haploid or diploid spores, respectively, indicating that meiosis starts before nuclear redistribution and cytokinesis. Our data suggest that the NUM1 protein is involved in the interaction of the G2 nucleus with the bud neck.
我们分离出了一个具有异常内部周期性的新基因（NUM1）。NUM1基因编码一种313 kDa的蛋白质，该蛋白质具有一个潜在的Ca2+结合位点和一个中央结构域，该结构域包含一个64个氨基酸多肽的12个几乎相同的串联重复序列。num1基因破坏的菌株生长正常，但含有许多在母细胞中有两个细胞核而不是在芽颈处有单个细胞核的出芽细胞，而所有未出芽的细胞都是单核的。这表明大多数G2期细胞核在迁移到颈部之前就在母细胞中分裂，然后两个子核中的一个迁移到芽中。此外，单倍体num1菌株在有丝分裂过程中倾向于二倍体化，纯合的num1二倍体或四倍体细胞形成孢子，分别形成许多带有多达八个单倍体或二倍体孢子的出芽子囊，这表明减数分裂在核重新分布和胞质分裂之前就开始了。我们的数据表明NUM1蛋白参与了G2期细胞核与芽颈的相互作用。
