title: Cross-regulation between Aurora B and Citron kinase controls midbody architecture in cytokinesis.
abstract: Cytokinesis culminates in the final separation, or abscission, of the two daughter cells at the end of cell division. Abscission relies on an organelle, the midbody, which forms at the intercellular bridge and is composed of various proteins arranged in a precise stereotypic pattern. The molecular mechanisms controlling midbody organization and function, however, are obscure. Here we show that proper midbody architecture requires cross-regulation between two cell division kinases, Citron kinase (CIT-K) and Aurora B, the kinase component of the chromosomal passenger complex (CPC). CIT-K interacts directly with three CPC components and is required for proper midbody architecture and the orderly arrangement of midbody proteins, including the CPC. In addition, we show that CIT-K promotes Aurora B activity through phosphorylation of the INCENP CPC subunit at the TSS motif. In turn, Aurora B controls CIT-K localization and association with its central spindle partners through phosphorylation of CIT-K's coiled coil domain. Our results identify, for the first time, a cross-regulatory mechanism between two kinases during cytokinesis, which is crucial for establishing the stereotyped organization of midbody proteins.
authors.affiliation: Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
authors.forename: Callum
authors.initials: C
authors.lastname: McKenzie
authors.affiliation: Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
authors.forename: Zuni I
authors.initials: ZI
authors.lastname: Bassi
authors.affiliation: Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, Warszawa 02-106, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Debski
authors.affiliation: Department of Life Sciences, University of Siena, Via A. Moro 4, Siena 53100, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Gottardo
authors.affiliation: Department of Life Sciences, University of Siena, Via A. Moro 4, Siena 53100, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Callaini
authors.affiliation: Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, Warszawa 02-106, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Dadlez
authors.affiliation: Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK ppd21@cam.ac.uk.
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: D'Avino
mesh_terms: D064107:Aurora Kinase B / Q000032:analysis / Q000378:metabolism*; D002455:Cell Division; D048749:Cytokinesis; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000032:analysis / Q000378:metabolism*; D010766:Phosphorylation; D060066:Protein Interaction Maps; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C115635:citron-kinase; D064107:Aurora Kinase B; D017346:Protein Serine-Threonine Kinases
keywords: Aurora B; Citron kinase; cell division; midbody