title: The Calcineurin Variant CnAβ1 Controls Mouse Embryonic Stem Cell Differentiation by Directing mTORC2 Membrane Localization and Activation.
abstract: Embryonic stem cells (ESC) have the potential to generate all the cell lineages that form the body. However, the molecular mechanisms underlying ESC differentiation and especially the role of alternative splicing in this process remain poorly understood. Here, we show that the alternative splicing regulator MBNL1 promotes generation of the atypical calcineurin Aβ variant CnAβ1 in mouse ESCs (mESC). CnAβ1 has a unique C-terminal domain that drives its localization mainly to the Golgi apparatus by interacting with Cog8. CnAβ1 regulates the intracellular localization and activation of the mTORC2 complex. CnAβ1 knockdown results in delocalization of mTORC2 from the membrane to the cytoplasm, inactivation of the AKT/GSK3β/β-catenin signaling pathway, and defective mesoderm specification. In summary, here we unveil the structural basis for the mechanism of action of CnAβ1 and its role in the differentiation of mESCs to the mesodermal lineage.
authors.affiliation: Myocardial Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Jesús M
authors.initials: JM
authors.lastname: Gómez-Salinero
authors.affiliation: Myocardial Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Marina M
authors.initials: MM
authors.lastname: López-Olañeta
authors.affiliation: Myocardial Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Ortiz-Sánchez
authors.affiliation: Myocardial Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Larrasa-Alonso
authors.affiliation: Myocardial Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Gatto
authors.affiliation: National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK.
authors.forename: Leanne E
authors.initials: LE
authors.lastname: Felkin
authors.affiliation: National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK; NIHR Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London SW7 2AZ, UK.
authors.forename: Paul J R
authors.initials: PJR
authors.lastname: Barton
authors.affiliation: Vascular Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Navarro-Lérida
authors.affiliation: Vascular Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Del Pozo
authors.affiliation: Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro Majadahonda, 28222 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: García-Pavía
authors.affiliation: Sanford Consortium for Regenerative Medicine, University of California San Diego (UCSD), La Jolla, CA 92037, USA.
authors.forename: Balaji
authors.initials: B
authors.lastname: Sundararaman
authors.affiliation: Pluripotent Cell Technology Unit, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Giovinazo
authors.affiliation: Sanford Consortium for Regenerative Medicine, University of California San Diego (UCSD), La Jolla, CA 92037, USA.
authors.forename: Gene W
authors.initials: GW
authors.lastname: Yeo
authors.affiliation: Myocardial Pathophysiology Program, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain; National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK. Electronic address: elara@cnic.es.
authors.forename: Enrique
authors.initials: E
authors.lastname: Lara-Pezzi
mesh_terms: D000818:Animals; D019703:Calcineurin / Q000032:analysis / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D006056:Golgi Apparatus / Q000378:metabolism; D000076225:Mechanistic Target of Rapamycin Complex 2; D051379:Mice; D000066450:Mouse Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D046912:Multiprotein Complexes / Q000032:analysis / Q000378:metabolism*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000032:analysis / Q000378:metabolism*
chemical_list: D046912:Multiprotein Complexes; D000076225:Mechanistic Target of Rapamycin Complex 2; D058570:TOR Serine-Threonine Kinases; D019703:Calcineurin; C557393:protein phosphatase 3, catalytic subunit, beta isoform, mouse
keywords: Akt; CnAβ1; Golgi apparatus; Rictor; calcineurin; mTOR; splicing; stem cells