HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 282, Issue 6, 4076-4084, February 9, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/6/4076    most recent M608187200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Suzuki, H. Articles by Takeuchi, N. Search for Related Content PubMed PubMed Citation Articles by Suzuki, H. Articles by Takeuchi, N. Social Bookmarking                      What's this?

Chaperone Properties of Mammalian Mitochondrial Translation Elongation Factor Tu^*

From the Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Building FSB-401, 5-1-5, Kashiwanoha, Kashiwa, Chiba Prefecture 277-8562, Japan

The main function of the prokaryotic translation elongation factor Tu (EF-Tu) and its eukaryotic counterpart eEF1A is to deliver aminoacyl-tRNA to the A-site on the ribosome. In addition to this primary function, it has been reported that EF-Tu from various sources has chaperone activity. At present, little information is available about the chaperone activity of mitochondrial EF-Tu. In the present study, we have examined the chaperone function of mammalian mitochondrial EF-Tu (EF-Tumt). We demonstrate that recombinant EF-Tumt prevents thermal aggregation of proteins and enhances protein refolding in vitro and that this EF-Tumt chaperone activity proceeds in a GTP-independent manner. We also demonstrate that, under heat stress, the newly synthesized peptides from the mitochondrial ribosome specifically co-immunoprecipitate with EF-Tumt and are destabilized in EF-Tumt-overexpressing cells. We show that most of the EF-Tumt localizes on the mitochondrial inner membrane where most mitochondrial ribosomes are found. We discuss the possible role of EF-Tumt chaperone activity in protein quality control in mitochondria, with regard to the recently reported in vivo chaperone function of eEF1A.

Received for publication, August 25, 2006 , and in revised form, October 20, 2006.

^* This work was supported, in part, by a grant for young scientists from JSPS (to N. T.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Fig. S1.

¹ To whom correspondence should be addressed: Tel./Fax: 81-47-136-3648; E-mail: nono{at}k.u-tokyo.ac.jp.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				P. A. Fowler, N. J. Dora, H. McFerran, M. R. Amezaga, D. W. Miller, R. G. Lea, P. Cash, A. S. McNeilly, N. P. Evans, C. Cotinot, et al. In utero exposure to low doses of environmental pollutants disrupts fetal ovarian development in sheep Mol. Hum. Reprod., May 1, 2008; 14(5): 269 - 280. [Abstract] [Full Text] [PDF]

				Y. Nozaki, N. Matsunaga, T. Ishizawa, T. Ueda, and N. Takeuchi HMRF1L is a human mitochondrial translation release factor involved in the decoding of the termination codons UAA and UAG. Genes Cells, May 1, 2008; 13(5): 429 - 438. [Abstract] [Full Text] [PDF]