Epithelial membrane protein EMP-1 (IPR003932)

Short name: EMP_1

Overlapping homologous superfamilies


Family relationships


The epithelial membrane proteins (EMP-1, -2 and -3), peripheral myelin protein 22 (PMP22), and lens fibre membrane intrinsic protein (LMIP) comprise a protein family on the basis of sequence and structural similarities [PMID: 7499407]. Each family member is a small hydrophobic membrane glycoprotein, ~160-170 amino acids in length, and shares a common predicted transmembrane (TM) topology of 4 TM domains, with intracellular N- and C-termini [PMID: 8884260].

EMP-1, previously termed tumour-associated membrane protein (TMP), was originally isolated from a mouse brain tumour [PMID: 8996089]. Human, rat and rabbit isoforms have also been identified. EMP-1 is expressed in a wide range of tissues, including heart, placenta, lung, skeletal muscle, kidney and small intestine [PMID: 9126480]. A role for the protein in the control of cell growth has been suggested [PMID: 7499407]. EMP-1 is expressed at high levels in proliferating cells, and at reduced levels in cells undergoing growth arrest [PMID: 8996089]. In contrast, PMP22, which is co-expressed with EMP-1 in a range of tissues, displays an inverse pattern of regulation, with high levels of expression in cultured cells undergoing growth arrest [PMID: 8996089]. It has therefore been proposed that these proteins may have reciprocal functions in the control of cell quiescence and proliferation.

GO terms

Biological Process

GO:0016049 cell growth

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.