Synb - syncytin b

Many different endogenous retrovirus families are expressed in normal placental tissue at high levels, suggesting that endogenous retroviruses are functionally important in reproduction. This gene is part of an endogenous retrovirus provirus that has inactivating mutations in the gag and pol genes. This gene is the envelope glycoprotein gene which appears to have been selectively preserved. The gene's protein product plays a major role in placental development and trophoblast fusion. The protein has the characteristics of a typical retroviral envelope protein, including a cleavage site that separates the surface (SU) and transmembrane (TM) proteins which form a heterodimer. [provided by RefSeq, Apr 2015]