Tetherin

Tetherin, also known as bone marrow stromal antigen 2, is a lipid raft associated protein that in humans is encoded by the BST2 gene.[3][4][5] In addition, tetherin has been designated as CD317 (cluster of differentiation 317). This protein is constitutively expressed in mature B cells, plasma cells and plasmacytoid dendritic cells, and in many other cells, it is only expressed as a response to stimuli from IFN pathway.[6]

BST2
Available structures PDB Human UniProt search: PDBe RCSB List of PDB id codes 2LK9, 2X7A, 2XG7, 3MQ7, 3MQ9, 3MQB, 3MQC, 3NWH, 4P6Z
Identifiers
Aliases	BST2, CD317, TETHERIN, Tetherin, bone marrow stromal cell antigen 2
External IDs	OMIM: 600534 HomoloGene: 48277 GeneCards: BST2
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19p13.11 Start 17,402,939 bp[1] End 17,405,630 bp[1]
RNA expression pattern More reference expression data
Gene ontology Molecular function • protein homodimerization activity • signal transducer activity • GO:0001948 protein binding • metalloendopeptidase inhibitor activity • RNA binding • identical protein binding Cellular component • cytoplasm • integral component of membrane • multivesicular body • endosome • late endosome • Golgi apparatus • membrane • cell membrane • integral component of plasma membrane • cell surface • apical plasma membrane • membrane raft • anchored component of membrane • extracellular exosome • cytosol • azurophil granule membrane Biological process • negative regulation of intracellular transport of viral material • regulation of actin cytoskeleton organization • response to interferon-gamma • immune system process • cell-cell signaling • response to virus • response to interferon-beta • multicellular organism development • B cell activation • negative regulation of viral genome replication • negative regulation of cell migration • humoral immune response • defense response to virus • type I interferon signaling pathway • negative regulation of cell growth • negative regulation of plasmacytoid dendritic cell cytokine production • response to interferon-alpha • positive regulation of I-kappaB kinase/NF-kappaB signaling • cellular proliferation • innate immune system • negative regulation of endopeptidase activity • neutrophil degranulation Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	684	n/a
Ensembl	ENSG00000130303	n/a
UniProt	Q10589	n/a
RefSeq (mRNA)	NM_004335	n/a
RefSeq (protein)	NP_004326	n/a
Location (UCSC)	Chr 19: 17.4 – 17.41 Mb	n/a
PubMed search	[2]	n/a
Wikidata
View/Edit Human

Gene activation

Tetherin is part of IFN-dependent antiviral response pathway. When the presence of virus and viral components is detected by recognition molecules such as (RIG-I), a cascades of interactions happen between signaling molecules, eventually the signal reaches the nucleus to upregulate the expression of interferon-stimulated genes (ISGs), this in turn activates IFN-a pathway to send the signal to neighboring cells, which causes upregulation in the expression of other ISGs and many viral restriction factors, such as tetherin.[7][8]

Function

Tetherin is a human cellular protein which inhibits retrovirus infection by preventing the diffusion of virus particles after budding from infected cells. Initially discovered as an inhibitor to HIV-1 infection in the absence of Vpu, tetherin has also been shown to inhibit the release of other RNA viruses such as the Lassa and Marburg virions[9][10] suggesting a common mechanism that inhibits enveloped virus release without interaction with viral proteins. In addition, tetherin also restricts neuroinvasion of the DNA virus HSV-1.[11]

Structure

Tetherin is a type 2 integral membrane protein, with the N-terminus in the cytoplasm, one membrane spanning domain, and a C-terminus modified by the addition of a glycosyl-phosphatidylinositol (gpi) anchor.[12] The transmembrane of tetherin is predicted to be a single alpha helix. The ectodomain consists of alpha helical coiled-coil region where the coils are slightly spread apart.[13] Although Tetherin is localized to the lipid rafts on the surface of the cells, they are endocytosed to be sorted through TGN by clathrin-dependent pathway. This is mediated by AP2 binding to the dual-tyrosine motif located in the cytosolic domain of tetherin.[5] When the virion buds from the surface of the cell, one of the tetherin membrane domains is in the new viral membrane, the other remains in the plasma membrane, tethering the virion to the cell. It is antagonized by the viral protein Vpu[14] which is thought to work by targeting tetherin for degradation via the β-TrCP2 dependent pathway.[15][16]

Tetherin exists as a dimer on the surface of cells, and prevention of dimerisation by mutating the cystine residues, prevents tetherin from inhibiting virus release, although it is still detectable in the cell. The stabilization of the protein through disulfide bond within the coiled coil region seems to be important in its function[6]

Interaction with different viruses

Tetherin is known to block many different types of enveloped viruses by tethering the budding virus like particles (VLPs) and inhibiting them from leaving the cell surface. Studies have shown that it is not the amino acid sequence, but the topology of tetherin is required for the tethering of virions on the cell surface.[6] Their unique topology allows them to be in the cell through their N-terminus while using the GPI anchor to attach to budding virions.[13] HIV-1 overcomes this restriction through vpu. Vpu interacts with tetherin by interacting with the protein at its transmembrane domain and recruiting β-TrCP2, which causes ubiquitination and degradation of tetherin. It has been recently shown that tetherin gene variants are associated with HIV disease progression underscoring the role of BST-2 in HIV type 1 infection.[17] Another primate lentivirus, SIV, also, counteracts tetherin by their removal from the plasma membrane.[18][19] KSHV protein K5 also targets tetherin for degradation through ubiquitination.[20] Ebola counteracts tethrin through two mechanism. VP35 of Ebola, inhibits multiple steps of IFN-signaling pathway, which blocks the induction of tetherin as a downstream effect. Also, it has been noted that the full-length Ebola GP may either translocate tetherin or disrupt the structure of tetherin.[7] Sendai virus proteins HN and F direct tethrin to endosomes or proteasome for degradation.[21] CHIKV protein nsP1 interacts with tetherin by disrupting the tetherin-virion complex formation.[22]

Cell-to-cell transmission through virological synapse in human retroviruses is also inhibited by tetherin. Tetherin aggregates virions and downmodulates the infectivity of the virions. It has also been suggested that tetherin may be involved in the structural integrity of the virological synapse.[6]

Other functions

Tetherin has also been predicted to be involved in cell adhesion and cell migration. Recently it has, also, been identified as the protein that help stabilize lipid rafts by joining nearby lipid rafts to form a cluster.[23] For some viruses, such as Dengue virus, tetherin inhibits the budding of virions as well as cell-to-cell transmission of the virus.[24] For human cytomegalovirus (HCMV), tetherin promotes entry of the virus, especially during cell differentiation. It has also been shown that tetherin is incorporated into newly formed virions.[25]

References

1. GRCh38: Ensembl release 89: ENSG00000130303 - Ensembl, May 2017
2. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
3. Ishikawa J, Kaisho T, Tomizawa H, Lee BO, Kobune Y, Inazawa J, Oritani K, Itoh M, Ochi T, Ishihara K (Aug 1995). "Molecular cloning and chromosomal mapping of a bone marrow stromal cell surface gene, BST2, that may be involved in pre-B-cell growth". Genomics. 26 (3): 527–34. doi:10.1016/0888-7543(95)80171-H. PMID 7607676.
4. "Entrez Gene: BST2 bone marrow stromal cell antigen 2".
5. Rollason R, Korolchuk V, Hamilton C, Schu P, Banting G (November 2007). "Clathrin-mediated endocytosis of a lipid-raft-associated protein is mediated through a dual tyrosine motif". Journal of Cell Science. 120 (Pt 21): 3850–8. doi:10.1242/jcs.003343. PMID 17940069.
6. Le Tortorec A, Willey S, Neil SJ (May 2011). "Antiviral inhibition of enveloped virus release by tetherin/BST-2: action and counteraction". Viruses. 3 (5): 520–40. doi:10.3390/v3050520. PMC 3185764. PMID 21994744.
7. Kühl A, Pöhlmann S (September 2012). "How ebola virus counters the interferon system". Zoonoses Public Health. 59 Suppl 2: 116–31. doi:10.1111/j.1863-2378.2012.01454.x. PMC 7165950. PMID 22958256.
8. Douglas JL, Gustin JK, Viswanathan K, Mansouri M, Moses AV, Früh K (May 2010). "The great escape: viral strategies to counter BST-2/tetherin". PLOS Pathogens. 6 (5): e1000913. doi:10.1371/journal.ppat.1000913. PMC 2869331. PMID 20485522.
9. Sakuma T, Noda T, Urata S, Kawaoka Y, Yasuda J (March 2009). "Inhibition of Lassa and Marburg virus production by tetherin". Journal of Virology. 83 (5): 2382–5. doi:10.1128/JVI.01607-08. PMC 2643706. PMID 19091864.
10. Thaczuk D (2008-02-11). "Tetherin: a newly discovered host cell protein that inhibits HIV replication". NAM AIDS Map.
11. Royer D, Carr J (December 2015). "A STING-dependent innate-sensing pathway mediates resistance to corneal HSV-1 infection via upregulation of the antiviral effector tetherin". Mucosal Immunology. 9 (4): 1065–75. doi:10.1038/mi.2015.124. PMC 4889566. PMID 26627457.
12. Andrew AJ, Miyagi E, Kao S, Strebel K (2009). "The formation of cysteine-linked dimers of BST-2/tetherin is important for inhibition of HIV-1 virus release but not for sensitivity to Vpu". Retrovirology. 6: 80. doi:10.1186/1742-4690-6-80. PMC 2754425. PMID 19737401.
13. Evans DT, Serra-Moreno R, Singh RK, Guatelli JC (September 2010). "BST-2/tetherin: a new component of the innate immune response to enveloped viruses". Trends in Microbiology. 18 (9): 388–96. doi:10.1016/j.tim.2010.06.010. PMC 2956607. PMID 20688520.
14. Neil SJ, Zang T, Bieniasz PD (January 2008). "Tetherin inhibits retrovirus release and is antagonized by HIV-1 Vpu". Nature. 451 (7177): 425–30. Bibcode:2008Natur.451..425N. doi:10.1038/nature06553. PMID 18200009.
15. Mangeat B, Gers-Huber G, Lehmann M, Zufferey M, Luban J, Piguet V (September 2009). "HIV-1 Vpu neutralizes the antiviral factor Tetherin/BST-2 by binding it and directing its beta-TrCP2-dependent degradation". PLOS Pathogens. 5 (9): e1000574. doi:10.1371/journal.ppat.1000574. PMC 2729927. PMID 19730691.
16. Iwabu Y, Fujita H, Kinomoto M, Kaneko K, Ishizaka Y, Tanaka Y, Sata T, Tokunaga K (December 2009). "HIV-1 accessory protein Vpu internalizes cell-surface BST-2/tetherin through transmembrane interactions leading to lysosomes". Journal of Biological Chemistry. 284 (50): 35060–72. doi:10.1074/jbc.M109.058305. PMC 2787367. PMID 19837671.
17. Laplana M, Caruz A, Pineda JA, Puig T, Fibla J (February 2013). "Association of BST-2 gene variants with HIV disease progression underscores the role of BST-2 in HIV type 1 infection". Journal of Infectious Diseases. 207 (3): 411–419. doi:10.1093/infdis/jis685. PMID 23148293.
18. Jia B, Serra-Moreno R, Neidermyer W, Rahmberg A, Mackey J, Fofana IB, Johnson WE, Westmoreland S, Evans DT (May 2009). "Species-specific activity of SIV Nef and HIV-1 Vpu in overcoming restriction by tetherin/BST2". PLOS Pathogens. 5 (5): e1000429. doi:10.1371/journal.ppat.1000429. PMC 2673686. PMID 19436700.
19. Harris RS, Hultquist JF, Evans DT (November 2012). "The restriction factors of human immunodeficiency virus". Journal of Biological Chemistry. 287 (49): 40875–83. doi:10.1074/jbc.R112.416925. PMC 3510791. PMID 23043100.
20. Mansouri M, Viswanathan K, Douglas JL, Hines J, Gustin J, Moses AV, Früh K (October 2009). "Molecular mechanism of BST2/tetherin downregulation by K5/MIR2 of Kaposi's sarcoma-associated herpesvirus". Journal of Virology. 83 (19): 9672–81. doi:10.1128/JVI.00597-09. PMC 2748026. PMID 19605472.
21. Bampi C, Rasga L, Roux L (March 2013). "Antagonism to human BST-2 / tetherin by Sendai virus glycoproteins". Journal of General Virology. 94 (Pt 6): 1211–9. doi:10.1099/vir.0.051771-0. PMC 3709622. PMID 23468424.
22. Jones PH, Maric M, Madison MN, Maury W, Roller RJ, Okeoma CM (March 2013). "BST-2/tetherin-mediated restriction of chikungunya (CHIKV) VLP budding is counteracted by CHIKV non-structural protein 1 (nsP1)". Virology. 438 (1): 37–49. doi:10.1016/j.virol.2013.01.010. PMC 4086190. PMID 23411007.
23. Billcliff PG, Rollason R, Prior I, Owen DM, Gaus K, Banting G (February 2013). "CD317/Tetherin is an organiser of membrane microdomains". Journal of Cell Science. 126 (Pt 7): 1553–64. doi:10.1242/jcs.112953. PMC 3647434. PMID 23378022.
24. Pan XB, Han JC, Cong X, Wei L (2012). "BST2/tetherin inhibits dengue virus release from human hepatoma cells". PLoS ONE. 7 (12): e51033. Bibcode:2012PLoSO...751033P. doi:10.1371/journal.pone.0051033. PMC 3517589. PMID 23236425.
25. Viswanathan K, Smith MS, Malouli D, Mansouri M, Nelson JA, Früh K (November 2011). "BST2/Tetherin enhances entry of human cytomegalovirus". PLOS Pathogens. 7 (11): e1002332. doi:10.1371/journal.ppat.1002332. PMC 3207899. PMID 22072961.

Further reading

• Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298.
• Furuya Y, Takasawa S, Yonekura H, Tanaka T, Takahara J, Okamoto H (1996). "Cloning of a cDNA encoding rat bone marrow stromal cell antigen 1 (BST-1) from the islets of Langerhans". Gene. 165 (2): 329–30. doi:10.1016/0378-1119(95)00540-M. PMID 8522202.
• Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID 9373149.
• Ohtomo T, Sugamata Y, Ozaki Y, Ono K, Yoshimura Y, Kawai S, Koishihara Y, Ozaki S, Kosaka M, Hirano T, Tsuchiya M (1999). "Molecular cloning and characterization of a surface antigen preferentially overexpressed on multiple myeloma cells". Biochemical and Biophysical Research Communications. 258 (3): 583–91. doi:10.1006/bbrc.1999.0683. PMID 10329429.
• Vidal-Laliena M, Romero X, March S, Requena V, Petriz J, Engel P (2006). "Characterization of antibodies submitted to the B cell section of the 8th Human Leukocyte Differentiation Antigens Workshop by flow cytometry and immunohistochemistry". Cellular Immunology. 236 (1–2): 6–16. doi:10.1016/j.cellimm.2005.08.002. PMID 16157322.
• Elortza F, Mohammed S, Bunkenborg J, Foster LJ, Nühse TS, Brodbeck U, Peck SC, Jensen ON (2006). "Modification-specific proteomics of plasma membrane proteins: identification and characterization of glycosylphosphatidylinositol-anchored proteins released upon phospholipase D treatment". Journal of Proteome Research. 5 (4): 935–43. doi:10.1021/pr050419u. PMID 16602701.

External links

• BST2+protein,+human at the US National Library of Medicine Medical Subject Headings (MeSH)

This article incorporates text from the United States National Library of Medicine, which is in the public domain.