Zim17, a novel zinc finger protein essential for protein import into mitochondria

Lena Burri; Katherine Vascotto; Steffen Fredersdorf; Ralph Tiedt; Michael N Hall; Trevor Lithgow

doi:10.1074/jbc.M409194200

Zim17, a novel zinc finger protein essential for protein import into mitochondria

J Biol Chem. 2004 Nov 26;279(48):50243-9. doi: 10.1074/jbc.M409194200. Epub 2004 Sep 21.

Authors

Lena Burri¹, Katherine Vascotto, Steffen Fredersdorf, Ralph Tiedt, Michael N Hall, Trevor Lithgow

Affiliation

¹ Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville 3010, Australia.

PMID: 15383543
DOI: 10.1074/jbc.M409194200

Abstract

Translocation of precursor proteins across the mitochondrial membranes requires the coordinated action of multisubunit translocases in the outer and inner membrane, and the driving force for translocation across the inner membrane is provided by the matrix-located heat shock protein 70 (mtHsp70). The central components of the protein import machinery are essential. Here we describe Zim17, an essential protein with a zinc finger motif involved in protein import into mitochondria. Comparative genomics suggested a correction to the open reading frame of YNL310c, the gene encoding Zim17 in Saccharomyces cerevisiae. The revised open reading frame codes for a classic mitochondrial targeting signal, which is processed from Zim17 in the mitochondrial matrix. Loss of Zim17 selectively diminishes import of proteins into the matrix of mitochondria, but this loss of Zim17 is partially suppressed by overexpression of the J-protein Pam18/Tim14. We propose that Zim17 functions as an example of a "fractured" J-protein, where a protein like Zim17 contributes a zinc finger domain to Type III J-proteins, in toto providing for substrate loading onto Hsp70.

Publication types

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

MeSH terms

Amino Acid Sequence
Arabidopsis Proteins / metabolism
Base Sequence
DNA-Binding Proteins / metabolism
HSP70 Heat-Shock Proteins / metabolism
Membrane Transport Proteins / metabolism
Mitochondria / metabolism*
Mitochondrial Membrane Transport Proteins / metabolism
Mitochondrial Precursor Protein Import Complex Proteins
Mitochondrial Proteins / genetics
Mitochondrial Proteins / metabolism*
Molecular Sequence Data
Protein Structure, Tertiary
Protein Transport / physiology
RNA-Binding Proteins / metabolism
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae / metabolism*
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / metabolism*
Zinc Fingers / genetics
Zinc Fingers / physiology*

Substances

Arabidopsis Proteins
DNA-Binding Proteins
HSP70 Heat-Shock Proteins
HUA1 protein, Arabidopsis
Membrane Transport Proteins
Mitochondrial Membrane Transport Proteins
Mitochondrial Precursor Protein Import Complex Proteins
Mitochondrial Proteins
PAM18 J protein, S cerevisiae
RNA-Binding Proteins
Saccharomyces cerevisiae Proteins
TIM44 protein, S cerevisiae
Tim14 protein, S cerevisiae
Zim17 protein, S cerevisiae