1. The INSR/AKT/mTOR pathway regulates the pace of myogenesis in a syndecan-3-dependent manner.
- Author
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Jones FK, Phillips AM, Jones AR, and Pisconti A
- Subjects
- Syndecan-3 genetics, Syndecan-3 metabolism, Cells, Cultured, Muscle Development genetics, TOR Serine-Threonine Kinases genetics, TOR Serine-Threonine Kinases metabolism, Cell Differentiation, Proto-Oncogene Proteins c-akt genetics, Proto-Oncogene Proteins c-akt metabolism, Muscle, Skeletal metabolism
- Abstract
Muscle stem cells (MuSCs) are indispensable for muscle regeneration. A multitude of extracellular stimuli direct MuSC fate decisions from quiescent progenitors to differentiated myocytes. The activity of these signals is modulated by coreceptors such as syndecan-3 (SDC3). We investigated the global landscape of SDC3-mediated regulation of myogenesis using a phosphoproteomics approach which revealed, with the precision level of individual phosphosites, the large-scale extent of SDC3-mediated regulation of signal transduction in MuSCs. We then focused on INSR/AKT/mTOR as a key pathway regulated by SDC3 during myogenesis and mechanistically dissected SDC3-mediated inhibition of insulin receptor signaling in MuSCs. SDC3 interacts with INSR ultimately limiting signal transduction via AKT/mTOR. Both knockdown of INSR and inhibition of AKT restore Sdc3
-/- MuSC differentiation to wild type levels. Since SDC3 is rapidly downregulated at the onset of differentiation, our study suggests that SDC3 acts a timekeeper to restrain proliferating MuSC response and prevent premature differentiation., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2022 Elsevier B.V. All rights reserved.)- Published
- 2022
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