title: Cytokinesis failure in RhoA-deficient mouse erythroblasts involves actomyosin and midbody dysregulation and triggers p53 activation.
abstract: RhoA GTPase has been shown in vitro in cell lines and in vivo in nonmammalian organisms to regulate cell division, particularly during cytokinesis and abscission, when 2 daughter cells partition through coordinated actomyosin and microtubule machineries. To investigate the role of this GTPase in the rapidly proliferating mammalian erythroid lineage, we developed a mouse model with erythroid-specific deletion of RhoA. This model was proved embryonic lethal as a result of severe anemia by embryonic day 16.5 (E16.5). The primitive red blood cells were enlarged, poikilocytic, and frequently multinucleated, but were able to sustain life despite experiencing cytokinesis failure. In contrast, definitive erythropoiesis failed and the mice died by E16.5, with profound reduction of maturing erythroblast populations within the fetal liver. RhoA was required to activate myosin-regulatory light chain and localized at the site of the midbody formation in dividing wild-type erythroblasts. Cytokinesis failure caused by RhoA deficiency resulted in p53 activation and p21-transcriptional upregulation with associated cell-cycle arrest, increased DNA damage, and cell death. Our findings demonstrate the role of RhoA as a critical regulator for efficient erythroblast proliferation and the p53 pathway as a powerful quality control mechanism in erythropoiesis.
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Diamantis G
authors.identifier: http://orcid.org/0000-0003-3680-0483
authors.initials: DG
authors.lastname: Konstantinidis
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Katie M
authors.identifier: http://orcid.org/0000-0002-0192-7209
authors.initials: KM
authors.lastname: Giger
authors.affiliation: College of Nursing, University of Cincinnati, Cincinnati, OH;
authors.forename: Mary
authors.initials: M
authors.lastname: Risinger
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Suvarnamala
authors.initials: S
authors.lastname: Pushkaran
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Ping
authors.initials: P
authors.lastname: Zhou
authors.affiliation: Biomedical Informatics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Phillip
authors.initials: P
authors.lastname: Dexheimer
authors.affiliation: Biomedical Informatics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Satwica
authors.initials: S
authors.lastname: Yerneni
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Paul
authors.initials: P
authors.lastname: Andreassen
authors.affiliation: Systems Biology of Signal Transduction, German Cancer Research Center, Center for Molecular Biology Alliance, Heidelberg, Germany; and.
authors.forename: Ursula
authors.initials: U
authors.lastname: Klingmüller
authors.affiliation: Department of Pediatrics, Center for Pediatric Biomedical Research, University of Rochester Medical Center, Rochester, NY.
authors.forename: James
authors.initials: J
authors.lastname: Palis
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH;
authors.forename: Theodosia A
authors.identifier: http://orcid.org/0000-0002-0426-9686
authors.initials: TA
authors.lastname: Kalfa
mesh_terms: D000205:Actomyosin / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis; D059447:Cell Cycle Checkpoints; D048749:Cytokinesis; D004249:DNA Damage; D020964:Embryo Loss / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004622:Embryo, Mammalian / Q000378:metabolism / Q000473:pathology; D004900:Erythroblasts / Q000166:cytology* / Q000378:metabolism / Q000473:pathology; D004920:Erythropoiesis; D005260:Female; D017353:Gene Deletion; D051379:Mice; D008810:Mice, Inbred C57BL; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000235:genetics* / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53; D000205:Actomyosin; D020742:rhoA GTP-Binding Protein