A MAMMALIAN DUAL SPECIFICITY PROTEIN-KINASE, NEK1, IS RELATED TO THE NIMA CELL-CYCLE REGULATOR AND HIGHLY EXPRESSED IN MEIOTIC GERM-CELLS
A MAMMALIAN DUAL SPECIFICITY PROTEIN-KINASE, NEK1, IS RELATED TO THE NIMA CELL-CYCLE REGULATOR AND HIGHLY EXPRESSED IN MEIOTIC GERM-CELLS
复制标题
DOI：
10.1002/j.1460-2075.1992.tb05435.x
复制
发表时间：
1992-10-01
期刊：
影响因子：
11.4
通讯作者：
PAWSON, T
中科院分区：
文献类型：
--
作者：
LETWIN, K;MIZZEN, L;PAWSON, T
用磷酸酪氨酸抗体筛选小鼠cDNA表达文库，导致重复分离编码774个氨基酸的新型哺乳动物蛋白激酶（称为Nek 1）的cDNA。Nek 1含有一个N-末端蛋白激酶结构域，它与NIMA的催化结构域最相似（42%同一性），NIMA是一种控制构巢曲霉有丝分裂起始的蛋白激酶。此外，Nek 1和NIMA都有一个长的基本C-末端延伸，因此在整体结构上相似。尽管其与抗磷酸酪氨酸抗体的鉴定，Nek 1包含蛋白丝氨酸/苏氨酸激酶的序列基序特征。Nek 1激酶结构域在细菌中表达时，主要在丝氨酸/苏氨酸上磷酸化外源底物，但也在酪氨酸上磷酸化外源底物，表明Nek 1是具有磷酸化所有三种羟基氨基酸的能力的双特异性激酶。与NIMA一样，Nek 1在体外优先磷酸化β-酪蛋白。对小鼠性腺中nek 1表达的原位RNA分析显示，nek 1在雄性和雌性生殖细胞中都有高水平表达，其分布与减数分裂中的作用一致。这些结果表明，Nek 1是一个哺乳动物的真菌NIMA细胞周期调节剂的亲戚。
Screening of mouse cDNA expression libraries with antibodies to phosphotyrosine resulted in repeated isolation of cDNAs that encode a novel mammalian protein kinase of 774 amino acids, termed Nek1. Nek1 contains an N-terminal protein kinase domain which is most similar (42% identity) to the catalytic domain of NIMA, a protein kinase which controls initiation of mitosis in Aspergillus nidulans. In addition, both Nek1 and NIMA have a long, basic C-terminal extension, and are therefore similar in overall structure. Despite its identification with anti-phosphotyrosine antibodies, Nek1 contains sequence motifs characteristic of protein serine/threonine kinases. The Nek1 kinase domain, when expressed in bacteria, phosphorylated exogenous substrates primarily on serine/threonine, but also on tyrosine, indicating that Nek1 is a dual specificity kinase with the capacity to phosphorylate all three hydroxyamino acids. Like NIMA, Nek1 preferentially phosphorylated beta-casein in vitro. In situ RNA analysis of nek1 expression in mouse gonads revealed a high level of expression in both male and female germ cells, with a distribution consistent with a role in meiosis. These results suggest that Nek1 is a mammalian relative of the fungal NIMA cell cycle regulator.