Identification and functional analysis of three isoforms of bovine BST-2.
Human BST-2 (hBST-2) has been identified as a cellular antiviral factor that blocks the release of various enveloped viruses. Orthologues of BST-2 have been identified in several species, including human, monkeys, pig, mouse, cat and sheep. All have been reported to possess antiviral activity. Duplication of the BST-2 gene has been observed in sheep and the paralogues are referred to as ovine BST-2A and BST2-B, although only a single gene corresponding to BST-2 has been identified in most species. In this study, we identified three isoforms of bovine BST-2, named bBST-2A1, bBST-2A2 and bBST-2B, in bovine cells treated with type I interferon, but not in untreated cells. Both bBST-2A1 and bBST-2A2 are posttranslationally modified by N-linked glycosylation and a GPI-anchor as well as hBST-2, while bBST-2B has neither of these modifications. Exogenous expression of bBST-2A1 or bBST-2A2 markedly reduced the production of bovine leukemia virus and vesicular stomatitis virus from cells, while the antiviral activity of bBST-2B was much weaker than those of bBST-2A1 and bBST-2A2. Our data suggest that bBST-2A1 and bBST-2A2 function as part of IFN-induced innate immunity against virus infection. On the other hand, bBST-2B may have a different physiological function from bBST-2A1 and bBST-2A2.
Department of Emerging Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
Eri
E
Takeda
So
S
Nakagawa
Yuki
Y
Nakaya
Atsushi
A
Tanaka
Takayuki
T
Miyazawa
Jiro
J
Yasuda
D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D003001:Cloning, Molecular; D004285:Dogs; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D016678:Genome / Q000235:genetics; D006801:Humans; D001909:Leukemia Virus, Bovine / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014721:Vesicular stomatitis Indiana virus / Q000187:drug effects; D021601:trans-Golgi Network / Q000187:drug effects / Q000378:metabolism
D000998:Antiviral Agents; D008562:Membrane Glycoproteins; D020033:Protein Isoforms