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

J. Biol. Chem., Vol. 280, Issue 9, 7597-7602, March 4, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/9/7597    most recent M409380200v1 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 Christensen, K. E. Articles by MacKenzie, R. E. Search for Related Content PubMed PubMed Citation Articles by Christensen, K. E. Articles by MacKenzie, R. E. Social Bookmarking                      What's this?

Disruption of the Mthfd1 Gene Reveals a Monofunctional 10-Formyltetrahydrofolate Synthetase in Mammalian Mitochondria^*

Karen E. Christensen, Harshila Patel, Uros Kuzmanov, Narciso R. Mejia, and Robert E. MacKenzie

From the Department of Biochemistry, McGill University, Montréal, Québec H3G 1Y6, Canada

The Mthfd1 gene encoding the cytoplasmic methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase enzyme (DCS) was inactivated in embryonic stem cells. The null embryonic stem cells were used to generate spontaneously immortalized fibroblast cell lines that exhibit the expected purine auxotrophy. Elimination of these cytoplasmic activities allowed for the accurate assessment of similar activities encoded by other genes in these cells. A low level of 10-formyltetrahydrofolate synthetase was detected and was shown to be localized to mitochondria. However, NADP-dependent methylenetetrahydrofolate dehydrogenase activity was not detected. Northern blot analysis suggests that a recently identified mitochondrial DCS (Prasannan, P., Pike, S., Peng, K., Shane, B., and Appling, D. R. (2003) J. Biol. Chem. 278, 43178–43187) is responsible for the synthetase activity. The lack of NADP-dependent dehydrogenase activity suggests that this RNA may encode a monofunctional synthetase. Moreover, examination of the primary structure of this novel protein revealed mutations in key residues required for dehydrogenase and cyclohydrolase activities. This monofunctional synthetase completes the pathway for the production of formate from formyltetrahydrofolate in the mitochondria in our model of mammalian one-carbon folate metabolism in embryonic and transformed cells.

Received for publication, August 16, 2004 , and in revised form, December 1, 2004.

^* 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.

To whom correspondence should be addressed: Dept. of Biochemistry, McIntyre Medical Sciences Bldg., McGill University, 3655 Promenade Sir William Osler, Montréal, Québec H3G 1Y6, Canada. Tel.: 514-398-7270; Fax: 514-398-7384; E-mail: robert.mackenzie{at}mcgill.ca.

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

This article has been cited by other articles:

				A. J. MacFarlane, C. A. Perry, H. H. Girnary, D. Gao, R. H. Allen, S. P. Stabler, B. Shane, and P. J. Stover Mthfd1 Is an Essential Gene in Mice and Alters Biomarkers of Impaired One-carbon Metabolism J. Biol. Chem., January 16, 2009; 284(3): 1533 - 1539. [Abstract] [Full Text] [PDF]

				L. Wang, Q. Ke, W. Chen, J. Wang, Y. Tan, Y. Zhou, Z. Hua, W. Ding, J. Niu, J. Shen, et al. Polymorphisms of MTHFD, Plasma Homocysteine Levels, and Risk of Gastric Cancer in a High-Risk Chinese Population Clin. Cancer Res., April 15, 2007; 13(8): 2526 - 2532. [Abstract] [Full Text] [PDF]

				K. E. Christensen, I. A. Mirza, A. M. Berghuis, and R. E. MacKenzie Magnesium and Phosphate Ions Enable NAD Binding to Methylenetetrahydrofolate Dehydrogenase-Methenyltetrahydrofolate Cyclohydrolase J. Biol. Chem., October 7, 2005; 280(40): 34316 - 34323. [Abstract] [Full Text] [PDF]