title: A conserved MADS-box phosphorylation motif regulates differentiation and mitochondrial function in skeletal, cardiac, and smooth muscle cells.
abstract: Exposure to metabolic disease during fetal development alters cellular differentiation and perturbs metabolic homeostasis, but the underlying molecular regulators of this phenomenon in muscle cells are not completely understood. To address this, we undertook a computational approach to identify cooperating partners of the myocyte enhancer factor-2 (MEF2) family of transcription factors, known regulators of muscle differentiation and metabolic function. We demonstrate that MEF2 and the serum response factor (SRF) collaboratively regulate the expression of numerous muscle-specific genes, including microRNA-133a (miR-133a). Using tandem mass spectrometry techniques, we identify a conserved phosphorylation motif within the MEF2 and SRF Mcm1 Agamous Deficiens SRF (MADS)-box that regulates miR-133a expression and mitochondrial function in response to a lipotoxic signal. Furthermore, reconstitution of MEF2 function by expression of a neutralizing mutation in this identified phosphorylation motif restores miR-133a expression and mitochondrial membrane potential during lipotoxicity. Mechanistically, we demonstrate that miR-133a regulates mitochondrial function through translational inhibition of a mitophagy and cell death modulating protein, called Nix. Finally, we show that rodents exposed to gestational diabetes during fetal development display muscle diacylglycerol accumulation, concurrent with insulin resistance, reduced miR-133a, and elevated Nix expression, as young adult rats. Given the diverse roles of miR-133a and Nix in regulating mitochondrial function, and proliferation in certain cancers, dysregulation of this genetic pathway may have broad implications involving insulin resistance, cardiovascular disease, and cancer biology.
authors.affiliation: Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.|The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: W
authors.initials: W
authors.lastname: Mughal
authors.affiliation: The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Nguyen
authors.affiliation: Department of Biology, York University, Toronto, ON, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Pustylnik
authors.affiliation: Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.|The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: S C
authors.initials: SC
authors.lastname: da Silva Rosa
authors.affiliation: Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.|The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Piotrowski
authors.affiliation: The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.|College of Nursing, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Chapman
authors.affiliation: Department of Biology, York University, Toronto, ON, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Du
authors.affiliation: Department of Biology, York University, Toronto, ON, Canada.
authors.forename: N S
authors.initials: NS
authors.lastname: Alli
authors.affiliation: Department of Biology, York University, Toronto, ON, Canada.|Department of Mathematics and Statistics, York University, Toronto, ON, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Grigull
authors.affiliation: Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada.|The Biology of Breathing Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: A J
authors.initials: AJ
authors.lastname: Halayko
authors.affiliation: Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Aliani
authors.affiliation: Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Topham
authors.affiliation: Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: R M
authors.initials: RM
authors.lastname: Epand
authors.affiliation: The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.|Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: G M
authors.initials: GM
authors.lastname: Hatch
authors.affiliation: The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.|Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: T J
authors.initials: TJ
authors.lastname: Pereira
authors.affiliation: The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.|Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Kereliuk
authors.affiliation: Department of Biology, York University, Toronto, ON, Canada.
authors.forename: J C
authors.initials: JC
authors.lastname: McDermott
authors.affiliation: Agriculture and Agrifood Canada, Morden, MB, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Rampitsch
authors.affiliation: The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.|Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: V W
authors.initials: VW
authors.lastname: Dolinsky
authors.affiliation: Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.|The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.|College of Nursing, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: J W
authors.initials: JW
authors.lastname: Gordon
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D019556:COS Cells; D002454:Cell Differentiation / Q000235:genetics*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D016640:Diabetes, Gestational; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D064326:MEF2 Transcription Factors / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D053078:Membrane Potential, Mitochondrial / Q000235:genetics; D035683:MicroRNAs / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D026362:Serum Response Factor / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D053719:Tandem Mass Spectrometry
chemical_list: D064326:MEF2 Transcription Factors; C548234:MIRN133 microRNA, human; D035683:MicroRNAs; D026362:Serum Response Factor