title: Aurora B-mediated phosphorylation of RASSF1A maintains proper cytokinesis by recruiting Syntaxin16 to the midzone and midbody.
abstract: Aurora B is critically involved in ensuring proper cytokinesis and maintaining genomic stability. The tumor suppressor RASSF1A regulates cell cycle progression by regulating mitotic progression, G(1)-S transition, and microtubule stability. We previously reported that both Aurora A and Aurora B phosphorylate RASSF1A, and showed that phosphorylation of RASSF1A by Aurora A blocks the inhibitory function of RASSF1A toward anaphase-promoting complex-Cdc20. However, the role of Aurora B-mediated RASSF1A phosphorylation remains unknown. Here, we show that phosphorylation of RASSF1A on Ser203 by Aurora B during late mitosis has a critical role in regulating cytokinesis. Notably, RASSF1A interacts with Syntaxin16, a member of the t-SNARE family, at the midzone and midbody during late mitosis. Aurora B is required for this interaction and for the subsequent recruitment of Syntaxin16 to the midzone and midbody, a prerequisite for the successful completion of cytokinesis. Furthermore, Aurora B depletion results in a failure of Syntaxin16 to properly localize to the midzone and midbody, a mislocalization that was prevented by overexpression of the phosphomimetic RASSF1A (S203D) mutant. Finally, either depletion of Syntaxin16 or expression of the nonphosphorylatable RASSF1A (S203A) mutant results in cytokinesis defects. Our findings implicate Aurora B-mediated phosphorylation of RASSF1A in the regulation of cytokinesis.
authors.affiliation: National Research Laboratory for Genomic Stability, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
authors.forename: Su Jung
authors.initials: SJ
authors.lastname: Song
authors.forename: Soon Jung
authors.initials: SJ
authors.lastname: Kim
authors.forename: Min Sup
authors.initials: MS
authors.lastname: Song
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Lim
mesh_terms: D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D048749:Cytokinesis / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D050765:Qa-SNARE Proteins / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D050765:Qa-SNARE Proteins; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases