Essential role of Mia40 in import and assembly of mitochondrial intermembrane space proteins
AUTOR(ES)
Chacinska, Agnieszka
FONTE
Nature Publishing Group
RESUMO
Mitochondria import nuclear-encoded precursor proteins to four different subcompartments. Specific import machineries have been identified that direct the precursor proteins to the mitochondrial outer membrane, inner membrane or matrix, respectively. However, a machinery dedicated to the import of mitochondrial intermembrane space (IMS) proteins has not been found so far. We have identified the essential IMS protein Mia40 (encoded by the Saccharomyces cerevisiae open reading frame YKL195w). Mitochondria with a mutant form of Mia40 are selectively inhibited in the import of several small IMS proteins, including the essential proteins Tim9 and Tim10. The import of proteins to the other mitochondrial subcompartments does not depend on functional Mia40. The binding of small Tim proteins to Mia40 is crucial for their transport across the outer membrane and represents an initial step in their assembly into IMS complexes. We conclude that Mia40 is a central component of the protein import and assembly machinery of the mitochondrial IMS.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=522791Documentos Relacionados
- Import of small Tim proteins into the mitochondrial intermembrane space
- An internal targeting signal directing proteins into the mitochondrial intermembrane space
- Mitochondrial Import of the ADP/ATP Carrier: the Essential TIM Complex of the Intermembrane Space Is Required for Precursor Release from the TOM Complex
- Role of the intermembrane-space domain of the preprotein receptor Tom22 in protein import into mitochondria.
- Tom40, the import channel of the mitochondrial outer membrane, plays an active role in sorting imported proteins