The novel mouse Polo-like kinase 5 responds to DNA damage and localizes in the nucleolus.
Polo-like kinases (Plk1-4) are emerging as an important class of proteins involved in many aspects of cell cycle regulation and response to DNA damage. Here, we report the cloning of a fifth member of the polo-like kinase family named Plk5. DNA and protein sequence analyses show that Plk5 shares more similarities with Plk2 and Plk3 than with Plk1 and Plk4. Consistent with this observation, we show that mouse Plk5 is a DNA damage inducible gene. Mouse Plk5 protein localizes predominantly to the nucleolus, and deletion of a putative nucleolus localization signal (NoLS) within its N-terminal moiety disrupts its nucleolar localization. Ectopic expression of Plk5 leads to cell cycle arrest in G1, decreased DNA synthesis, and to apoptosis, a characteristic it shares with Plk3. Interestingly, in contrast to mouse Plk5 gene, the sequence of human Plk5 contains a stop codon that produces a truncated protein lacking part of the kinase domain.
Andrysik
Zdenek
Z
Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.
Bernstein
William Z
WZ
Deng
Li
L
Myer
David L
DL
Li
Ya-Qin
YQ
Tischfield
Jay A
JA
Stambrook
Peter J
PJ
Bahassi
El Mustapha
el M
D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002466:Cell Nucleolus / Q000201:enzymology*; D003001:Cloning, Molecular; D004249:DNA Damage; D016193:G1 Phase; D006801:Humans; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D017421:Sequence Analysis; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D016159:Tumor Suppressor Protein p53; D017346:Protein Serine-Threonine Kinases; C549900:polo-like kinase 5, human; C549899:polo-like kinase 5, mouse