Affordable Access

deepdyve-link
Publisher Website

Single amino acid mutations in the Saccharomyces cerevisiae rhomboid peptidase, Pcp1p, alter mitochondrial morphology

Authors
  • Huddleston, Mary Elizabeth1
  • Xiao, Ningyu1
  • Both, Andries Pieter1
  • Gordon, Donna M.1
  • 1 Mississippi State University, USA , (United States)
Type
Published Article
Journal
Cell Biology International
Publisher
Wiley (John Wiley & Sons)
Publication Date
Sep 03, 2019
Volume
44
Issue
1
Pages
200–215
Identifiers
DOI: 10.1002/cbin.11219
PMID: 31441130
PMCID: PMC6972574
Source
PubMed Central
Keywords
License
Unknown
External links

Abstract

Key to mitochondrial activities is the maintenance of mitochondrial morphology, specifically cristae structures formed by the invagination of the inner membrane that are enriched in proteins of the electron transport chain. In Saccharomyces cerevisiae , these cristae folds are a result of the membrane fusion activities of Mgm1p and the membrane‐bending properties of adenosine triphosphate (ATP) synthase oligomerization. An additional protein linked to mitochondrial morphology is Pcp1p, a serine protease responsible for the proteolytic processing of Mgm1p. Here, we have used hydroxylamine‐based random mutagenesis to identify amino acids important for Pcp1p peptidase activity. Using this approach we have isolated five single amino acid mutants that exhibit respiratory growth defects that correlate with loss of mitochondrial genome stability. Reduced Pcp1p protease activity was confirmed by immunoblotting with the accumulation of improperly processed Mgm1p. Ultra‐structural analysis of mitochondrial morphology in these mutants found a varying degree of defects in cristae organization. However, not all of the mutants presented with decreased ATP synthase complex assembly as determined by blue native polyacrylamide gel electrophoresis. Together, these data suggest that there is a threshold level of processed Mgm1p required to maintain ATP synthase super‐complex assembly and mitochondrial cristae organization.

Report this publication

Statistics

Seen <100 times