MRPS27 is a pentatricopeptide repeat domain protein required for the translation of mitochondrially encoded proteins

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Rapid Isolation of the Mitoribosome from HEK Cells
09:33

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Stefan M K Davies1, Maria I G Lopez Sanchez, Reena Narsai

  • 1Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6000, Australia.

FEBS Letters
|July 31, 2012
PubMed

Insights

Supernumerary mitochondrial ribosomal protein 27 (MRPS27) associates with mitochondrial RNA but is not essential for RNA processing. MRPS27 is crucial for mitochondrial protein synthesis, impacting respiratory complexes and enzyme activity.

Area of Science:

  • Mitochondrial biology
  • Molecular genetics
  • Protein synthesis

Background:

  • Pentatricopeptide repeat (PPR) proteins regulate mitochondrial RNA metabolism and translation.
  • Mitochondrial function relies on proper RNA metabolism and protein synthesis.
  • The role of uncharacterized PPR proteins like MRPS27 in mitochondrial function is largely unknown.

Purpose of the Study:

  • To investigate the function of the uncharacterized PPR protein, supernumerary mitochondrial ribosomal protein of the small subunit 27 (MRPS27).
  • To determine MRPS27's role in mitochondrial RNA metabolism, ribosomal subunit stability, and protein synthesis.

Main Methods:

  • Investigated MRPS27's association with mitochondrial 12S rRNA and tRNA(Glu).
  • Assessed the impact of MRPS27 knockdown on mitochondrial RNA processing and ribosomal subunit stability.
  • Evaluated MRPS27's requirement for mitochondrial protein synthesis and its effect on respiratory complexes.

Main Results:

  • MRPS27 associates with 12S rRNA and tRNA(Glu) without affecting their abundance.
  • MRPS27 is not required for mitochondrial RNA processing or small ribosomal subunit stability.
  • MRPS27 is essential for mitochondrial protein synthesis; its knockdown reduces respiratory complexes and cytochrome c oxidase activity.

Conclusions:

  • MRPS27 plays a vital role in mitochondrial protein synthesis, not RNA processing.
  • Dysfunction of MRPS27 impairs mitochondrial respiration by affecting protein synthesis and complex assembly.

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