Arama E, Yanai A, Kilfin G, Bernstein A, Motro B
Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
Oncogene. 1998 Apr 9;16(14):1813-23. doi: 10.1038/sj.onc.1201710.
NIMA protein kinase is a major regulator of progression into mitosis in Aspergillus nidulans. Dominant negative forms of NIMA protein prevent entrance into mitosis in HeLa cells, suggesting that mammals have a similar pathway. We have reported previously the isolation of a murine NIMA-related kinase, designated Nek1, and more recently several additional NIMA-related human kinases have been cloned. The existence of several mammalian NIMA-related genes raises the questions of whether the different mammalian members have redundant, overlapping or distinct functions, and whether these functions are related to the role of NIMA in controlling mitosis. To address these questions we have studied the expression patterns of the different murine nek genes. To this end, we isolated a murine nek2 cDNA and compared its patterns of expression, during both gametogenesis and embryogenesis, to those of nek1. Both genes were highly expressed in developing germ cells, albeit in distinct patterns. In both females and males, nek1 is expressed much earlier than nek2, suggesting only limited ability for functional redundancy. Surprisingly, a striking specificity of nek1 expression was found: high levels of nek1 RNA were observed in distinct regions of the nervous system, most notably in neurons of the peripheral ganglia. These patterns suggest that the different mammalian NIMA-related kinases participate in different phases of the meiotic process and may also have functions other than cell cycle control.
NIMA蛋白激酶是构巢曲霉进入有丝分裂过程的主要调节因子。NIMA蛋白的显性负性形式可阻止HeLa细胞进入有丝分裂，这表明哺乳动物具有类似的途径。我们之前报道过一种小鼠NIMA相关激酶的分离，命名为Nek1，最近又克隆了几个额外的NIMA相关人类激酶。几个哺乳动物NIMA相关基因的存在引发了这样的问题：不同的哺乳动物成员是否具有冗余、重叠或不同的功能，以及这些功能是否与NIMA在控制有丝分裂中的作用相关。为了解决这些问题，我们研究了不同小鼠nek基因的表达模式。为此，我们分离了一个小鼠nek2 cDNA，并将其在配子发生和胚胎发生过程中的表达模式与nek1的表达模式进行了比较。这两个基因在发育中的生殖细胞中均高度表达，尽管表达模式不同。在雌性和雄性中，nek1的表达都比nek2早得多，这表明功能冗余的能力有限。令人惊讶的是，发现了nek1表达的显著特异性：在神经系统的不同区域观察到高水平的nek1 RNA，最显著的是在周围神经节的神经元中。这些模式表明，不同的哺乳动物NIMA相关激酶参与减数分裂过程的不同阶段，并且可能还具有细胞周期控制以外的功能。
