TMEM243 (Transmembrane protein 243) is a protein-coding gene located on human chromosome 7 at cytoband 7q21.12. The gene spans approximately 24,427 base pairs (from position 87,196,160 to 87,220,587 on chromosome 7, per GRCh38). It is also known by the aliases C7orf23, MGC4175, and MM-TRAG (MDR1- and Mitochondrial Taxol Resistance-Associated Gene).
Gene and Protein Characteristics
The TMEM243 gene has multiple transcript variants (splice variants) and encodes a small protein. The primary isoform (TMEM243-201) is 118 amino acids in length with a molecular mass of approximately 13.4 kDa. It is predicted to contain three transmembrane regions and is classified as a predicted membrane protein. The protein is predicted to be an integral component of the membrane, with subcellular localization predicted to include both membrane and intracellular compartments.
Expression
According to the Human Protein Atlas, TMEM243 shows broad expression across tissues. In humans, it is notably expressed in the thyroid gland (left and right lobes), lung, lymph node, spleen, pancreas, and granulocytes. In mice, expression is observed in spermatids, liver, lung, kidney, and granulocytes, among other tissues.
Function and Research Significance
The precise biological function of TMEM243 remains incompletely characterized. However, a notable study by Duan et al. (2004) identified MM-TRAG (MGC4175), the protein encoded by this gene, as a novel intracellular mitochondrial protein associated with the taxol- and doxorubicin-resistant phenotype in human cancer cell lines. This suggests a potential role in drug resistance mechanisms in cancer.
Orthologs and Conservation
TMEM243 is conserved across many mammalian species, including mouse (Tmem243, chromosome 5), pig, cow, rat, and American pika. The gene has approximately 200 orthologues identified across species.
Database Identifiers
- Entrez Gene (Human): 79161
- Ensembl: ENSG00000135185
- UniProt: Q9BU79
- HGNC: HGNC:21707
- OMIM: 616993
References
- Duan Z, Brakora KA, Seiden MV (September 2004). "MM-TRAG (MGC4175), a novel intracellular mitochondrial protein, is associated with the taxol- and doxorubicin-resistant phenotype in human cancer cell lines." Gene. 340 (1): 53–9.
- Wikipedia: "TMEM243" and "Transmembrane protein 243"
- Human Protein Atlas: ENSG00000135185-TMEM243
- UniProtKB: Q9BU79
