RNA subunit of mitochondrial RNA-processing enzyme is induced by contractile activity in striated muscle.

Journal Article (Journal Article)

A small RNA encoded within the nucleus of yeast and mammalian cells is an essential subunit of a mitochondrial RNA-processing endonuclease (RNase MRP) that generates primers for mitochondrial DNA (mtDNA) replication. We examined expression of MRP-RNA in specialized subtypes of mammalian striated muscles that differ markedly in respiratory activity and in muscles subjected to chronic stimulation via the motor nerve, a potent stimulus to mitochondrial biogenesis. MRP-RNA was more abundant in mitochondria-rich cardiac and slow-twitch skeletal muscles than in glycolytic fast-twitch skeletal muscles. Forced contractile activity resulting from nerve stimulation increased expression of MRP-RNA by 3.5-fold within the first day and by 14-fold within 14 days. Changes in abundance of MRP-RNA preceded but otherwise occurred in parallel to changes in specific activity of citrate synthase, a marker of mitochondrial proliferation shown previously to correlate with mtDNA copy number in this model. Another small RNA (U1) also was induced transiently (1-3 days) by nerve stimulation, but such changes were not sustained and were of less magnitude (< 4-fold) than changes in MRP-RNA. These findings are consistent with the hypothesis that MRP-RNA may have a regulatory function with respect to mtDNA replication and mitochondrial biogenesis.

Full Text

Duke Authors

Cited Authors

  • Ordway, GA; Li, K; Hand, GA; Williams, RS

Published Date

  • December 1993

Published In

Volume / Issue

  • 265 / 6 Pt 1

Start / End Page

  • C1511 - C1516

PubMed ID

  • 7506487

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpcell.1993.265.6.C1511


  • eng

Conference Location

  • United States