A J-protein is an essential subunit of the presequence translocase–associated protein import motor of mitochondria
Open Access
- 24 November 2003
- journal article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 163 (4) , 707-713
- https://doi.org/10.1083/jcb.200308004
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.Keywords
This publication has 26 references indexed in Scilit:
- The Mitochondrial Presequence TranslocaseCell, 2002
- Molecular Chaperones in the Cytosol: from Nascent Chain to Folded ProteinScience, 2002
- J-domain Protein, Jac1p, of Yeast Mitochondria Required for Iron Homeostasis and Activity of Fe-S Cluster ProteinsJournal of Biological Chemistry, 2001
- Protein translocation pathways of the mitochondrionFEBS Letters, 2000
- Protein translocation: Is Hsp70 pulling my chain?Current Biology, 1999
- The J-domain family and the recruitment of chaperone powerTrends in Biochemical Sciences, 1998
- The Hsp70 and Hsp60 Chaperone MachinesCell, 1998
- The Tim core complex defines the number of mitochondrial translocation contact sites and can hold arrested preproteins in the absence of matrix Hsp70-Tim44The EMBO Journal, 1997
- Role of mitochondrial GrpE and phosphate in the ATPase cycle of matrix Hsp70Journal of Molecular Biology, 1997
- Can Hsp70 proteins act as force-generating motors?Cell, 1995