Cytokinesis involves a nontranscriptional function of the Hippo pathway effector YAP

Sci Signal. 2016 Mar 1;9(417):ra23. doi: 10.1126/scisignal.aaa9227.

Abstract

YAP is a transcriptional coactivator that controls organ expansion and differentiation and is inhibited by the Hippo pathway in cells in interphase. Here, we demonstrated that, during mitosis, YAP localized to the midbody and spindle, subcellular structures that are involved in cytokinesis, the process by which contraction of the cytoskeleton produces two daughter cells. Furthermore, YAP was phosphorylated by CDK1, a kinase that promotes cell cycle progression. Knockdown of YAP by shRNA or expression of a nonphosphorylatable form of YAP delayed the separation of daughter cells (called abscission) and induced a cytokinesis phenotype associated with increased contractile force, membrane blebbing and bulges, and abnormal spindle orientation. Consequently, these defects led to an increased frequency of multinucleation, micronuclei, and aneuploidy. YAP was required for proper localization of proteins that regulate contraction during cytokinesis, including ECT2, MgcRacGap, Anillin, and RHOA. In addition, depletion of YAP increased the phosphorylation of myosin light chain, which would be expected to activate the contractile activity of myosin II, the molecular motor involved in cytokinesis. The polarity scaffold protein PATJ coprecipitated with YAP and colocalized with YAP at the cytokinesis midbody, and knockdown of PATJ phenocopied the cytokinetic defects and spindle orientation alterations induced by either YAP depletion or expression of a nonphosphorylatable YAP mutant. Together, these results reveal an unanticipated role for YAP in the proper organization of the cytokinesis machinery during mitosis through interaction with the polarity protein PATJ.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • CDC2 Protein Kinase
  • Cell Line
  • Contractile Proteins / metabolism
  • Cyclin-Dependent Kinases / metabolism
  • Cytokinesis / genetics
  • Cytokinesis / physiology*
  • GTPase-Activating Proteins / metabolism
  • HeLa Cells
  • Humans
  • Immunoblotting
  • Microscopy, Confocal
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism
  • RNA Interference
  • Signal Transduction / genetics
  • Signal Transduction / physiology*
  • Tight Junction Proteins / genetics
  • Tight Junction Proteins / metabolism
  • Transcription Factors
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Contractile Proteins
  • ECT2 protein, human
  • GTPase-Activating Proteins
  • PATJ protein, human
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • Tight Junction Proteins
  • Transcription Factors
  • YAP1 protein, human
  • anillin
  • mgcRacGAP
  • Hippo protein, human
  • Protein-Serine-Threonine Kinases
  • CDC2 Protein Kinase
  • CDK1 protein, human
  • Cyclin-Dependent Kinases
  • rhoA GTP-Binding Protein