A J-protein is an essential subunit of the presequence translocase-associated protein import motor of mitochondria

Kaye N Truscott; Wolfgang Voos; Ann E Frazier; Maria Lind; Yanfeng Li; Andreas Geissler; Jan Dudek; Hanne Müller; Albert Sickmann; Helmut E Meyer; Chris Meisinger; Bernard Guiard; Peter Rehling; Nikolaus Pfanner

doi:10.1083/jcb.200308004

A J-protein is an essential subunit of the presequence translocase-associated protein import motor of mitochondria

J Cell Biol. 2003 Nov 24;163(4):707-13. doi: 10.1083/jcb.200308004.

Authors

Kaye N Truscott¹, Wolfgang Voos, Ann E Frazier, Maria Lind, Yanfeng Li, Andreas Geissler, Jan Dudek, Hanne Müller, Albert Sickmann, Helmut E Meyer, Chris Meisinger, Bernard Guiard, Peter Rehling, Nikolaus Pfanner

Affiliation

¹ Institut für Biochemie und Molekularbiologie, Universität Freiburg, D-79104 Freiburg, Germany.

Abstract

Transport of preproteins into the mitochondrial matrix is mediated by the presequence translocase-associated motor (PAM). Three essential subunits of the motor are known: mitochondrial Hsp70 (mtHsp70); the peripheral membrane protein Tim44; and the nucleotide exchange factor Mge1. We have identified the fourth essential subunit of the PAM, an essential inner membrane protein of 18 kD with a J-domain that stimulates the ATPase activity of mtHsp70. The novel J-protein (encoded by PAM18/YLR008c/TIM14) is required for the interaction of mtHsp70 with Tim44 and protein translocation into the matrix. We conclude that the reaction cycle of the PAM of mitochondria involves an essential J-protein.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence / genetics
Base Sequence / genetics
Carrier Proteins / metabolism
Cells, Cultured
DNA, Complementary / analysis
DNA, Complementary / genetics
HSP70 Heat-Shock Proteins / metabolism
Heat-Shock Proteins / metabolism
Macromolecular Substances
Membrane Proteins / genetics
Membrane Proteins / isolation & purification*
Membrane Proteins / metabolism
Membrane Transport Proteins / genetics
Membrane Transport Proteins / isolation & purification*
Membrane Transport Proteins / metabolism
Mitochondria / metabolism*
Mitochondrial Membrane Transport Proteins*
Mitochondrial Precursor Protein Import Complex Proteins
Molecular Chaperones
Molecular Motor Proteins / metabolism*
Molecular Sequence Data
Protein Transport / physiology*
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / isolation & purification*
Saccharomyces cerevisiae Proteins / metabolism

Substances

Carrier Proteins
DNA, Complementary
HSP70 Heat-Shock Proteins
Heat-Shock Proteins
MGE1 protein, S cerevisiae
Macromolecular Substances
Membrane Proteins
Membrane Transport Proteins
Mitochondrial Membrane Transport Proteins
Mitochondrial Precursor Protein Import Complex Proteins
Molecular Chaperones
Molecular Motor Proteins
PAM18 J protein, S cerevisiae
Saccharomyces cerevisiae Proteins
TIM44 protein, S cerevisiae