A micropeptide encoded by a putative long noncoding RNA regulates muscle performance

Cell. 2015 Feb 12;160(4):595-606. doi: 10.1016/j.cell.2015.01.009. Epub 2015 Jan 29.

Abstract

Functional micropeptides can be concealed within RNAs that appear to be noncoding. We discovered a conserved micropeptide, which we named myoregulin (MLN), encoded by a skeletal muscle-specific RNA annotated as a putative long noncoding RNA. MLN shares structural and functional similarity with phospholamban (PLN) and sarcolipin (SLN), which inhibit SERCA, the membrane pump that controls muscle relaxation by regulating Ca(2+) uptake into the sarcoplasmic reticulum (SR). MLN interacts directly with SERCA and impedes Ca(2+) uptake into the SR. In contrast to PLN and SLN, which are expressed in cardiac and slow skeletal muscle in mice, MLN is robustly expressed in all skeletal muscle. Genetic deletion of MLN in mice enhances Ca(2+) handling in skeletal muscle and improves exercise performance. These findings identify MLN as an important regulator of skeletal muscle physiology and highlight the possibility that additional micropeptides are encoded in the many RNAs currently annotated as noncoding.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Calcium / metabolism
  • Calcium-Binding Proteins / metabolism
  • Humans
  • Male
  • Mice
  • Models, Molecular
  • Molecular Sequence Data
  • Muscle Proteins / chemistry
  • Muscle Proteins / genetics*
  • Muscle Proteins / metabolism*
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / metabolism*
  • Myocardium / metabolism
  • Protein Structure, Secondary
  • Proteolipids / metabolism
  • RNA, Long Noncoding / genetics*
  • RNA, Long Noncoding / metabolism
  • Sarcoplasmic Reticulum / metabolism
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases / metabolism
  • Sequence Alignment

Substances

  • Calcium-Binding Proteins
  • Muscle Proteins
  • Proteolipids
  • RNA, Long Noncoding
  • myoregulin, human
  • myoregulin, mouse
  • phospholamban
  • sarcolipin
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Calcium