Alternative titles; symbols
HGNC Approved Gene Symbol: EMP1
Cytogenetic location: 12p13.1 Genomic coordinates (GRCh38) : 12:13,196,726-13,219,941 (from NCBI)
Ben-Porath and Benvenisty (1996) cloned a cDNA encoding epithelial membrane protein-1 (EMP1), named TMP by them, using RT-PCR on human embryo kidney RNA. Ruegg et al. (1996) independently isolated a cDNA encoding EMP1, termed B4B by them, using differential display PCR. The predicted 157-amino acid EMP1 protein contains 4 transmembrane domains and 2 potential N-linked glycosylation sites in the first extracellular loop.
Chen et al. (1997) found that EMP1, named CL-20 by them, shares 39% amino acid identity with peripheral myelin protein-22 (PMP22; 601097); the conserved amino acids are located predominantly within the membrane-spanning domains. Using Northern blot analysis, Chen et al. (1997) detected a 2.8-kb EMP1 transcript in most of the adult tissues examined, but not in brain, liver, pancreas, or peripheral blood leukocytes.
Due to the high amino acid sequence homology among PMP22, EMP1, EMP2 (602334), and EMP3 (602335), Ben-Porath and Benvenisty (1996) proposed that these proteins are members of a novel family. Using RT-PCR, Ben-Porath and Benvenisty (1996) detected EMP1 expression in embryonic kidney, brain, and gut, but not in liver and thymus. Based on the suggested functions of PMP22, they proposed that EMP1 is involved in cell-cell interactions and the control of cell proliferation.
Chen et al. (1997) found that the EMP1 gene contains 5 exons and 4 introns, and they noted that the exon/intron junctions are located at the same positions as those of PMP22, suggesting that EMP1 and PMP22 arose by duplication of a common ancestral gene.
Marvin et al. (1995) localized the EMP1 gene to chromosome 12 using a somatic cell hybrid panel. By fluorescence in situ hybridization, Chen et al. (1997) and Ruegg et al. (1996) mapped the EMP1 gene to 12p12 and 20q12-q13.1, respectively. By FISH, somatic cell hybridization, and radiation hybrid analysis, Liehr et al. (1999) confirmed assignment of the EMP1 gene to chromosome 12p12.3. Ben Porath et al. (1998) mapped the homologous gene in the mouse to chromosome 6.
Gefitinib is a chemotherapeutic agent that competes for the ATP-binding site on EGF receptor (EGFR; 131550). To study gefitinib resistance in tumors, Jain et al. (2005) developed a gefitinib-resistant adenocarcinoma xenograft in nude mice. Acquisition of gefitinib resistance correlated with surface expression of Emp1. EMP1 expression also correlated with reduced response to gefitinib in lung cancer patient samples, as well as with clinical progression to secondary gefitinib resistance. EMP1 expression and gefitinib resistance were independent of gefitinib-sensitizing EGFR somatic mutations.
Ben-Porath, I., Benvenisty, N. Characterization of a tumor-associated gene, a member of a novel family of genes encoding membrane glycoproteins. Gene 183: 69-75, 1996. [PubMed: 8996089] [Full Text: https://doi.org/10.1016/s0378-1119(96)00475-1]
Ben Porath, I., Kozak, C. A., Benvenisty, N. Chromosomal mapping of Tmp (Emp1), Xmp (Emp2), and Ymp (Emp3), genes encoding membrane proteins related to Pmp22. Genomics 49: 443-447, 1998. [PubMed: 9615230] [Full Text: https://doi.org/10.1006/geno.1998.5238]
Chen, Y., Medvedev, A., Ruzanov, P., Marvin, K. W., Jetten, A. M. cDNA cloning, genomic structure, and chromosome mapping of the human epithelial membrane protein CL-20 gene (EMP1), a member of the PMP22 family. Genomics 41: 40-48, 1997. [PubMed: 9126480] [Full Text: https://doi.org/10.1006/geno.1997.4524]
Jain, A., Tindell, C. A., Laux, I., Hunter, J. B., Curran, J., Galkin, A., Afar, D. E., Aronson, N., Shak, S., Natale, R. B., Agus, D. B. Epithelial membrane protein-1 is a biomarker of gefitinib resistance. Proc. Nat. Acad. Sci. 102: 11858-11863, 2005. [PubMed: 16087880] [Full Text: https://doi.org/10.1073/pnas.0502113102]
Liehr, T., Kuhlenbaumer, G., Wulf, P., Taylor, V., Suter, U., Van Broeckhoven, C., Lupski, J. R., Claussen, U., Rautenstrauss, B. Regional localization of the human epithelial membrane protein genes 1, 2, and 3 (EMP1, EMP2, EMP3) to 12p12.3, 16p13.2, and 19q13.3. Genomics 58: 106-108, 1999. [PubMed: 10331954] [Full Text: https://doi.org/10.1006/geno.1999.5803]
Marvin, K. W., Fujimoto, W., Jetten, A. M. Identification and characterization of a novel squamous cell-associated gene related to PMP22. J. Biol. Chem. 270: 28910-28916, 1995. [PubMed: 7499420] [Full Text: https://doi.org/10.1074/jbc.270.48.28910]
Ruegg, C. L., Wu, H., Fagnoni, F. F., Engleman, E. G., Laus, R. B4B, a novel growth-arrest gene, is expressed by a subset of progenitor/pre-B lymphocytes negative for cytoplasmic mu-chain. J. Immun. 157: 72-80, 1996. [PubMed: 8683158]