title: Regulation of PP2Cm expression by miRNA-204/211 and miRNA-22 in mouse and human cells.
abstract: OBJECTIVE
  The mitochondrial targeted 2C-type serine/threonine protein phosphatase (PP2Cm) is encoded by the gene PPM1K and is highly conserved among vertebrates. PP2Cm plays a critical role in branched-chain amino acid catabolism and regulates cell survival. Its expression is dynamically regulated by the nutrient environment and pathological stresses. However, little is known about the molecular mechanism underlying the regulation of PPM1K gene expression. In this study, we aimed to reveal how PPM1K expression is affected by miRNA-mediated post-transcriptional regulation.
  
  
  METHODS
  Computational analysis based on conserved miRNA binding motifs was applied to predict the candidate miRNAs that potentially affect PPM1K expression. Dual-luciferase reporter assay was performed to verify the miRNAs' binding sites in the PPM1K gene and their influence on PPM1K 3'UTR activity. We further over-expressed the mimics of these miRNAs in human and mouse cells to examine whether miRNAs affected the mRNA level of PPM1K.
  
  
  RESULTS
  Computational analysis identified numerous miRNAs potentially targeting PPM1K. Luciferase reporter assays demonstrated that the 3'UTR of PPM1K gene contained the recognition sites of miR-204 and miR-211. Overexpression of these miRNAs in human and mouse cells diminished the 3'UTR activity and the endogenous mRNA level of PPM1K. However, the miR-22 binding site was found only in human and not mouse PPM1K 3'UTR. Accordingly, PPM1K 3'UTR activity was suppressed by miR-22 overexpression in human but not mouse cells.
  
  
  CONCLUSIONS
  These data suggest that different miRNAs contribute to the regulation of PP2Cm expression in a species-specific manner. miR-204 and miR-211 are efficient in both mouse and human cells, while miR-22 regulates PP2Cm expression only in human cells.
authors.affiliation: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors.forename: Bang-fen
authors.initials: BF
authors.lastname: Pan
authors.affiliation: Division of Molecular Medicine, Department of Anesthesiology, Medicine and Physiology, Molecular Biology Institute, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California, Los Angeles, CA 90095, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Gao
authors.affiliation: Division of Molecular Medicine, Department of Anesthesiology, Medicine and Physiology, Molecular Biology Institute, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California, Los Angeles, CA 90095, USA.
authors.forename: Shu-xun
authors.initials: SX
authors.lastname: Ren
authors.affiliation: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.|Division of Molecular Medicine, Department of Anesthesiology, Medicine and Physiology, Molecular Biology Institute, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California, Los Angeles, CA 90095, USA.
authors.forename: Yi-bin
authors.initials: YB
authors.lastname: Wang
authors.affiliation: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.|Division of Molecular Medicine, Department of Anesthesiology, Medicine and Physiology, Molecular Biology Institute, Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California, Los Angeles, CA 90095, USA.
authors.forename: Hai-peng
authors.initials: HP
authors.lastname: Sun
authors.affiliation: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors.forename: Mei-yi
authors.initials: MY
authors.lastname: Zhou
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D010749:Phosphoprotein Phosphatases / Q000235:genetics*; D000071636:Protein Phosphatase 2C; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; C549404:MIRN204 microRNA, human; C549405:MIRN211 microRNA, human; C548375:MIRN22 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; C000607462:PPM1K protein, human; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C