ERVWE1

HERV-W_7q21.2 provirus ancestral Env polyprotein also known as syncytin or enverin, is a protein encoded by an is_associated_with::endogenous viral element. In humans, the syncytin gene is called ERVWE1.

Function
Syncytins are genes encoding proteins derived from the envelope protein of endogenous retroviral elements that have been captured and domesticated on multiple occasions and independently in diverse mammalian species. is_associated_with::Gene knockout of syncytin genes in mice provides evidence for their absolute requirement for placenta development and embryo survival.

The human ERVWE1 locus is derived from a human endogenous retrovirus-W (HERV-W) is_associated_with::provirus located on chromosome 7. This provirus has inactivating mutations in the gag and pol genes, but the envelope glycoprotein gene has been selectively preserved. The product of this gene, syncytin, is expressed in the placental is_associated_with::syncytiotrophoblast and is involved in fusion of the is_associated_with::cytotrophoblast cells to form the syncytial layer of the placenta. The protein has the characteristics of a typical retroviral envelope protein, including a is_associated_with::furin cleavage site that separates the surface (SU) and transmembrane (TM) proteins which form a heterodimer.

Clinical significance
Mutations in the ERVWE1 gene have been associated with is_associated_with::multiple sclerosis and is_associated_with::schizophrenia.