Protein Domain : Peripheral myelin protein PMP22 IPR003936

Type	Family
Description	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 [ ]. 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 [].PMP22, also termed growth-arrest specific protein (GAS3), is a structural component of compact myelin in the peripheral nervous system. Aberrant expression of the PMP22 gene, and mutations in the protein, are associated with a variety of hereditary peripheral motor and sensory neuropathies [ ]. An intra-chromosomal duplication containing the PMP22 gene is found in the majority of patients suffering from the autosomal dominant demyelinating neuropathy Charcot-Marie-Tooth disease 1A (CMT1A) []. In addition, rare point mutations in PMP22 have been found in non-duplication CMT1A patients and in the severe congenital peripheral neuropathy Dejerine-Sottas syndrome [].PMP22 is also implicated in the control of cell proliferation. Its expression levels are up-regulated in cells undergoing growth arrest [ ], and it has been shown that modulating PMP22 levels in cultured Schwann cells exerts a profound effect on the length of the G1 phase of the cell cycle []. It has also been demonstrated that over-expression of PMP22 in NIH 3T3 fibroblast cells induces apoptosis [].
Short Name	PMP22