Tim23, a protein import component of the mitochondrial inner membrane, is required for normal activity of the multiple conductance channel, MCC

Timothy A. Lohret, Robert E. Jensen, Kathleen W. Kinnally

Research output: Contribution to journalArticle

Abstract

We previously showed that the conductance of a mitochondrial inner membrane channel, called MCC, was specifically blocked by peptides corresponding to mitochondrial import signals. To determine if MCC plays a role in protein import, we examined the relationship between MCC and Tim23p, a component of the protein import complex of the mitochondrial inner membrane. We find that antibodies against Tim23p, previously shown to inhibit mitochondrial protein import, inhibit MCC activity. We also find that MCC activity is altered in mitochondria isolated from yeast carrying the tim23-1 mutation. In contrast to wild-type MCC, we find that the conductance of MCC from the tim23-1 mutant is not significantly blocked by mitochondrial presequence peptides. Tim23 antibodies and the tim23-1 mutation do not, however, alter the activity of PSC, a presequence-peptide sensitive channel in the mitochondrial outer membrane. Our results show that Tim23p is required for normal MCC activity and raise the possibility that precursors are translocated across the inner membrane through the pore of MCC.

Original languageEnglish (US)
Pages (from-to)377-386
Number of pages10
JournalJournal of Cell Biology
Volume137
Issue number2
DOIs
StatePublished - Apr 21 1997

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Mitochondrial Membranes
Peptides
Mutation
Antibodies
Mitochondrial Proteins
Ion Channels
Mitochondria
Proteins
Yeasts
Membranes
peptide sensitive channel

ASJC Scopus subject areas

  • Cell Biology

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Tim23, a protein import component of the mitochondrial inner membrane, is required for normal activity of the multiple conductance channel, MCC. / Lohret, Timothy A.; Jensen, Robert E.; Kinnally, Kathleen W.

In: Journal of Cell Biology, Vol. 137, No. 2, 21.04.1997, p. 377-386.

Research output: Contribution to journalArticle

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