The Avian Retroviral Receptor Tva Mediates the Uptake of Transcobalamin Bound Vitamin B-12 (Cobalamin)

0543825 - ÚMG 2022 RIV US eng J - Journal Article
Krchlíková, Veronika - Mikešová, J. - Geryk, Josef - Bařinka, Cyril - Nexo, E. - Fedosov, S.N. - Kosla, Jan - Kučerová, Dana - Reinišová, Markéta - Hejnar, Jiří - Elleder, Daniel
The Avian Retroviral Receptor Tva Mediates the Uptake of Transcobalamin Bound Vitamin B-12 (Cobalamin).
Journal of Virology. Roč. 95, č. 8 (2021), č. článku e02136-20. ISSN 0022-538X. E-ISSN 1098-5514
R&D Projects: GA MŠMT(CZ) LM2018129; GA ČR(CZ) GA17-23675S; GA MŠMT(CZ) LQ1604; GA MŠMT(CZ) ED1.1.00/02.0109
Institutional support: RVO:68378050 ; RVO:86652036 ; RVO:68378050
Keywords : avian leukosis virus * cobalamin * receptor * retrovirus
OECD category: Virology; Virology (BTO-N)
Impact factor: 6.549, year: 2021
Method of publishing: Limited access
https://journals-asm-org.d360prx.biomed.cas.cz/doi/epub/10.1128/JVI.02136-20

The avian sarcoma and leukosis viruses (ASLVs) are important chicken pathogens. Some of the virus subgroups, including ASLV-A and K, utilize the Tva receptor for cell entrance. Though Tva was identified 3 decades ago, its physiological function remains unknown. Previously, we have noted an intriguing resemblance and orthology between the chicken gene coding for Tva and the human gene coding for CD320, a receptor involved in cellular uptake of transcobalamin (TC) in complex with vitamin B12/cobalamin (Cbl). Here, we show that both the transmembrane and the glycosylphosphatidylinositol (GPI)-anchored form of Tva in the chicken cell line DF-1 promotes the uptake of Cbl with the help of expressed and purified chicken TC. The uptake of TC-Cbl complex was monitored using an isotope-or fluorophore-labeled Cbl. We show that (i) TC-Cbl is internalized in chicken cells, and (ii) the uptake is lower in the Tva-knockout cells and higher in Tva-overexpressing cells when compared with that of wild-type chicken cells. The relation between physiological function of Tva and its role in infection was elaborated by showing that infection with ASLV subgroups (targeting Tva) impairs the uptake of TC-Cbl, while this is not the case for cells infected with ASLV-B (not recognized by Tva). In addition, exposure of the cells to a high concentration of TC-Cbl alleviates the infection with Tva-dependent ASLV.
Permanent Link: http://hdl.handle.net/11104/0320943