NEK7 is a centrosomal kinase critical for microtubule nucleation.
NIMA in Aspergillus nidulans is a mitotic kinase for chromosome condensation and segregation. We characterized NEK7, a human homologue of Aspergillus NIMA. NEK7 was located at the centrosome throughout the cell cycle. Temporal localization of NEK7 at midbody of the cytokinetic cell was also observed. NEK7 knockdown by RNAi caused a prometaphase arrest of the cell cycle with monopolar or disorganized spindle. We propose that such defects in spindle assembly are resulted from reduction in microtubule nucleation activity at the centrosome. In consistent to the proposal, we observed a decrease in the centrosomal gamma-tubulin levels and reduction of the microtubule re-growth activity in the NEK7-suppressed cells. In addition, it was evident that NEK7 was directly involved in cytokinesis.
Kim
Sunghwan
S
Department of Biological Sciences and Research Center for Functional Cellulomics, Seoul National University, Seoul 151-742, Republic of Korea.
Lee
Kwanwoo
K
Rhee
Kunsoo
K
D002467:Cell Nucleus / Q000378:metabolism*; D018385:Centrosome / Q000201:enzymology*; D048749:Cytokinesis; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000378:metabolism*; D000072379:NIMA-Related Kinases; D009687:Nuclear Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*
D009687:Nuclear Proteins; C512685:NEK7 protein, human; D000072379:NIMA-Related Kinases; D017346:Protein Serine-Threonine Kinases