*138330
GLUTATHIONE S-TRANSFERASE, MICROSOMAL, 1; MGST1

Alternative titles; symbols
GLUTATHIONE S-TRANSFERASE 12; GST12

HGNC Approved Gene Symbol: MGST1

Cytogenetic location: 12p12.3     Genomic coordinates (GRCh37): 12:16,500,075 - 16,517,343 (from NCBI)

TEXT
The glutathione S-transferases are products of a gene superfamily. These dimeric proteins catalyze the conjugation of glutathione with a variety of xenobiotics and their reactive metabolites. They are composed of 3 classes of subunits according to protein sequence similarity and antibody crossreactivity: alpha, mu, and pi. A fourth GST is a unique membrane-bound transferase that is structurally distinct from the cytosolic forms. It has no amino acid or nucleic acid sequence homology to the cytosolic enzymes and may function as a trimer rather than as a dimer.

By screening a human liver cDNA library with a rat microsomal GST cDNA, DeJong et al. (1988) identified cDNAs encoding MGST1. Northern blot analysis revealed that MGST1 is expressed as a 0.95-kb mRNA in liver. The predicted 154-amino acid protein shares 83% amino acid identity with rat microsomal GST. Using the MGST1 cDNA, DeJong et al. (1989, 1990) characterized the MGST1 gene by genomic blotting and assigned the gene to chromosome 12 by study of a panel of mouse-human somatic cell hybrid DNAs.

Kelner et al. (1996) determined that the GST12 gene spans 12.8 kb and comprises 4 exons and 3 introns. The entire coding sequence resides on exons 2, 3, and 4. Kelner et al. (1996) also confirmed the presence of an upstream false start and a stop codon which could produce a heptadecapeptide and depress translation initiation at the authentic AUG. The authors stated, however, that initiation is suppressed at the false start codon due to either the closeness of the upstream stop codon or the suboptimal context of the codon.

REFERENCES
1. DeJong, J. L., Mohandas, T., Tu, C.-P. D. The gene for the microsomal glutathione S-transferase is on human chromosome 12. Genomics 6: 379-382, 1990. [PubMed: 2307478, related citations] [Full Text: Elsevier Science, Pubget]

2. DeJong, J. L., Mohandas, T. K., Tu, C.-P. D. Mapping of the human microsomal glutathione S-transferase gene to chromosome 12. (Abstract) Cytogenet. Cell Genet. 51: 986 only, 1989.

3. DeJong, J. L., Morgenstern, R., Jornvall, H., DePierre, J. W., Tu, C.-P. D. Gene expression of rat and human microsomal glutathione S-transferases. J. Biol. Chem. 263: 8430-8436, 1988. [PubMed: 3372534, related citations] [Full Text: HighWire Press, Pubget]

4. Kelner, M. J., Stokely, M. N., Stovall, N. E., Montoya, M. A. Structural organization of the human microsomal glutathione S-transferase gene (GST12). Genomics 36: 100-103, 1996. [PubMed: 8812420, related citations] [Full Text: Elsevier Science, Pubget]

Contributors: Rebekah S. Rasooly - updated : 6/2/1998
Jennifer P. Macke - updated : 10/16/1996
Creation Date: Victor A. McKusick : 6/2/1989
Edit History: psherman : 06/17/1998
psherman : 6/2/1998
alopez : 2/6/1998
alopez : 9/18/1997
carol : 10/16/1996
carol : 5/11/1994
carol : 7/21/1993
supermim : 3/16/1992
carol : 2/29/1992
carol : 6/12/1991
supermim : 5/1/1990