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A Role for the Mitochondrial Protein Mrpl44 in Maintaining OXPHOS Capacity

Janet H C Yeo1, Jarrod P J Skinner2, Matthew J Bird3

  • 1Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia; St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia.

Plos One
|July 30, 2015
PubMed

Insights

Mitochondrial protein Mrpl44 is located in the mitochondrial matrix and is part of the large ribosomal subunit. It regulates mitochondrial gene expression, impacting cellular respiration and ATP synthesis.

Area of Science:

  • Mitochondrial biology
  • Molecular genetics
  • Protein biochemistry

Background:

  • Mrpl44 (Mitochondrial ribosomal protein L44) is a mammalian protein containing RNase III domains.
  • Previous studies suggested its association with the mitochondrial ribosome, but its precise localization was unknown.

Purpose of the Study:

  • To determine the subcellular localization of Mrpl44.
  • To investigate the function of Mrpl44 in mitochondrial gene expression and cellular respiration.

Main Methods:

  • Immunofluorescence microscopy
  • Subcellular fractionation
  • Gene expression manipulation
  • Assessment of ATP synthesis and cellular respiration

Main Results:

  • Mrpl44 is localized to the mitochondrial matrix.
  • Mrpl44 forms multimers and is a component of the large mitochondrial ribosomal subunit.
  • Mrpl44 regulates mtDNA-encoded gene expression at both RNA and protein levels.
  • Altered Mrpl44 expression impacts cellular ATP synthesis and respiratory capacity.

Conclusions:

  • Mrpl44 is a crucial regulator of mitochondrial gene expression.
  • Mrpl44 plays a significant role in maintaining mitochondrial oxidative phosphorylation (OXPHOS) capacity.

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