Abstract
Polo-like kinase 1 (Plk1) plays essential roles during multiple stages of mitosis by phosphorylating a number of substrates. Here, we report that the atypical protein kinase Rio2 is a novel substrate of Plk1 and can be phosphorylated by Plk1 at Ser-335, Ser-380, and Ser-548. Overexpression of Rio2 causes a prolonged mitotic exit whereas knockdown of Rio2 accelerates mitotic progression, suggesting that Rio2 is required for the proper mitotic progression. Overexpression of phospho-mimicking mutant Rio2 S3D but not the nonphosphorylatable mutant Rio2 S3A displays a profile similar to that of wild-type Rio2. These results indicate that the phosphorylation status of Rio2 correlates with its function in mitosis. Furthermore, time-lapse imaging data show that overexpression of Rio2 but not Rio2 S3A results in a slowed metaphase-anaphase transition. Collectively, these findings strongly indicate that the Plk1-mediated phosphorylation of Rio2 regulates metaphase-anaphase transition during mitotic progression.
Highlights
Rio2 is a protein kinase and involved in ribosomal subunit maturation
We demonstrate that Rio2 is a novel substrate of Polo-like kinase 1 (Plk1) and its phosphorylation by Plk1 plays an important role in the regulation of proper metaphase-anaphase transition
The result indicated that the interaction between Plk1 and Rio2 was independent of Plk1 kinase activity (Fig. 1B)
Summary
Rio is a protein kinase and involved in ribosomal subunit maturation. Results: Rio is a novel substrate of Plk. Polo-like kinase 1 (Plk1) plays essential roles during multiple stages of mitosis by phosphorylating a number of substrates. Timelapse imaging data show that overexpression of Rio but not Rio S3A results in a slowed metaphase-anaphase transition These findings strongly indicate that the Plk1-mediated phosphorylation of Rio regulates metaphase-anaphase transition during mitotic progression. Numerous substrates of Plk have been identified and studied extensively these years These findings were helpful to a better understanding of the multiple roles of Plk in cell cycle regulation. We demonstrate that Rio is a novel substrate of Plk and its phosphorylation by Plk plays an important role in the regulation of proper metaphase-anaphase transition
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
