Record Details

Role of the mTORC1 Complex in Satellite Cell Activation by RNAInduced Mitochondrial Restoration: Dual Control of Cyclin D1 through MicroRNAs

EPrints@IICB

View Archive Info
 
 
Field Value
 
Title Role of the mTORC1 Complex in Satellite Cell Activation by RNAInduced Mitochondrial Restoration: Dual Control of Cyclin D1 through MicroRNAs
 
Creator Jash, Sukanta
Dhar, Gunjan
Ghosh, Utpalendu
Adhya, Samit
 
Subject Molecular & Human Genetics
 
Description During myogenesis, satellite stem cells (SCs) are induced to proliferate and differentiate to myogenic precursors. The role of energy sensors such as the AMP-activated protein kinase (AMPK) and the mammalian Target of Rapamycin (mTOR) in SC activation is unclear. We previously observed that upregulation of ATP through RNA-mediated mitochondrial restoration (MR) accelerates SC activation following skeletal muscle injury. We show here that during regeneration, the AMPK-CRTC2-CREB and Raptor-mTORC-4EBP1 pathways were rapidly activated. The phosho-CRTC2-CREB complex was essential for myogenesis and activated transcription of the critical cell cycle regulator cyclin D1 (Ccnd1). Knockdown (KD) of either mTORC or its subunit
Raptor delayed SC activation without influencing the differentiation program. KD of 4EBP1 had no effect on SC activation but enhanced myofiber size. mTORC1 positively regulated Ccnd1 translation but destabilized Ccnd1 mRNA. These antithetical effects of mTORC1 were mediated by two microRNAs (miRs) targeted to the 3= untranslated region (UTR) of Ccnd1 mRNA: miR-1 was downregulated in mTORC-KD muscle, and depletion of miR-1 resulted in increased levels of mRNA without any effect on Ccnd1 protein. In contrast, miR-26a was upregulated upon mTORC depletion, while anti-miR-26a oligonucleotide specifically stimulated Ccnd1 protein expression. Thus, mTORC may act as a timer of satellite cell proliferation during myogenesis.
 
Publisher American Society for Microbiology
 
Date 2014
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://www.eprints.iicb.res.in/2159/1/MOLECULAR_AND_CELLULAR_BIOLOGY__V_34(_19)_3594%2D3606;2014[35].pdf
Jash, Sukanta and Dhar, Gunjan and Ghosh, Utpalendu and Adhya, Samit (2014) Role of the mTORC1 Complex in Satellite Cell Activation by RNAInduced Mitochondrial Restoration: Dual Control of Cyclin D1 through MicroRNAs. Molecular and Cellular Biology, 34 (19). pp. 3594-3606.
 
Relation http://dx.doi.org/10.1128/MCB.00742-14
http://www.eprints.iicb.res.in/2159/