![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011
3To whom correspondence should be addressed. E-mail: kschalin{at}iastate.edu
Glycine N-methyltransferase (GNMT) functions to regulate S-adenosylmethionine (SAM) levels and the ratio of SAM/S-adenosylhomocysteine (SAH). SAM is a universal methyl group donor and the up-regulation of GNMT may lead to wastage of methyl groups required for transmethylation reactions. Previously, we demonstrated that dietary treatment of rats with 13-cis-retinoic acid (CRA) decreased the hepatic concentration of SAM and the SAH ratio. Here, we examined the ability of CRA, as well as all-trans-retinoic acid (ATRA), to regulate hepatic GNMT as a potential basis for our earlier observations. Rats were fed either a control (10% casein + 0.3% L-methionine) diet or a control diet supplemented with L-methionine (10 g/kg diet). Rats from each group were orally given ATRA, CRA (both at 30 µmol/kg body), or vehicle daily for 7 d. For control rats, administration of both CRA and ATRA elevated the hepatic GNMT activity 49% and 34%, respectively, compared with the control group. Similar results were exhibited by rats fed the methionine-supplemented diet. Moreover, the retinoid-induced elevations in enzyme activity were reflected in the abundance of GNMT protein. To our knowledge, this is the first report of a nutritional compound that induces GNMT activity at the transcriptional and/or translational level.
KEY WORDS: • retinoic acid • S-adenosylmethionine • transmethylation • glycine N-methyltransferase • rats
This article has been cited by other articles:
|
|
 |
|
  K. T. Williams, T. A. Garrow, and K. L. Schalinske Type I Diabetes Leads to Tissue-Specific DNA Hypomethylation in Male Rats J. Nutr., November 1, 2008; 138(11): 2064 - 2069. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Beagle, T. L. Yang, J. Hung, E. A. Cogger, D. J. Moriarty, and M. A. Caudill The Glycine N-Methyltransferase (GNMT) 1289 C->T Variant Influences Plasma Total Homocysteine Concentrations in Young Women after Restricting Folate Intake J. Nutr., December 1, 2005; 135(12): 2780 - 2785. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Tanghe, T. A. Garrow, and K. L. Schalinske Triiodothyronine Treatment Attenuates the Induction of Hepatic Glycine N-Methyltransferase by Retinoic Acid and Elevates Plasma Homocysteine Concentrations in Rats J. Nutr., November 1, 2004; 134(11): 2913 - 2918. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. M. Nieman, M. J. Rowling, T. A. Garrow, and K. L. Schalinske Modulation of Methyl Group Metabolism by Streptozotocin-induced Diabetes and All-trans-retinoic Acid J. Biol. Chem., October 29, 2004; 279(44): 45708 - 45712. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. K. Ozias and K. L. Schalinske All-trans-Retinoic Acid Rapidly Induces Glycine N-methyltransferase in a Dose-Dependent Manner and Reduces Circulating Methionine and Homocysteine Levels in Rats J. Nutr., December 1, 2003; 133(12): 4090 - 4094. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Rowling and K. L. Schalinske Retinoic Acid and Glucocorticoid Treatment Induce Hepatic Glycine N-Methyltransferase and Lower Plasma Homocysteine Concentrations in Rats and Rat Hepatoma Cells J. Nutr., November 1, 2003; 133(11): 3392 - 3398. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T.-L. Tseng, Y.-P. Shih, Y.-C. Huang, C.-K. Wang, P.-H. Chen, J.-G. Chang, K.-T. Yeh, Y.-M. A. Chen, and K. H. Buetow Genotypic and Phenotypic Characterization of a Putative Tumor Susceptibility Gene, GNMT, in Liver Cancer Cancer Res., February 1, 2003; 63(3): 647 - 654. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Rowling, M. H. McMullen, D. C. Chipman, and K. L. Schalinske Hepatic Glycine N-Methyltransferase Is Up-Regulated by Excess Dietary Methionine in Rats J. Nutr., September 1, 2002; 132(9): 2545 - 2550. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Rowling, M. H. McMullen, and K. L. Schalinske Vitamin A and Its Derivatives Induce Hepatic Glycine N-Methyltransferase and Hypomethylation of DNA in Rats J. Nutr., March 1, 2002; 132(3): 365 - 369. [Abstract] [Full Text] [PDF]
|
|
