Retroviral envelope proteins mediate receptor recognition and membrane fusion during early infection. Endogenous envelope proteins may have kept, lost or modified their original function during evolution. This endogenous envelope protein has lost its fusogenic properties. It can inhibit cell growth through decrease expression of cyclin B1 and increased expression of p21 in vitro.
SU mediates receptor recognition.
TM anchors the envelope heterodimer to the viral membrane through one transmembrane domain. The other hydrophobic domain, called fusion peptide, mediates fusion of the viral membrane with the target cell membrane.
Subcellular Location:
Virion.
Tissue Specificity:
Expressed at higher level in adrenal, sebaceous glands and placenta. Expressed at lower level in bone marrow, brain, breast, colon, heart, kidney, liver, lung, ovary, PBL, prostate, skin, spleen, testis, thymus, thyroid, trachea.
Post-translational modifications:
Specific enzymatic cleavages in vivo yield the mature SU and TM proteins (By similarity). Has been mainly detected in vivo as an 65 kDa unprocessed polyprotein precursor.
The CXXC motif is highly conserved across a broad range of retroviral envelope proteins. It is thought to participate in the formation of a labile disulfide bond possibly with the CX6CC motif present in the transmembrane protein. Isomerization of the intersubunit disulfide bond to an SU intrachain disulfide bond is thought to occur upon receptor recognition in order to allow membrane fusion.
Similarity:
Belongs to the gamma type-C retroviral envelope protein family. HERV class-I R env subfamily.
SWISS:
Q14264
Gene ID:
2086
Database links:
Entrez Gene: 2086 Human
Omim: 131170 Human
SwissProt: Q14264 Human
Unigene: 250693 Human
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