Fluorescent TAP as a platform for virus-induced degradation of the antigenic peptide transporter
Magda Wąchalska , Małgorzata Graul , Patrique Praest , Rutger D. Luteijn , Aleksandra W. Babnis , Emmanuel J. H. J. Wiertz , Krystyna Bieńkowska-Szewczyk , Andrea D. Lipińska
AbstractTransporter associated with antigen processing (TAP), a key player in the major histocompatibility complex class I-restricted antigen presentation, makes an attractive target for viruses that aim to escape the immune system. Mechanisms of TAP inhibition vary among virus species. Bovine herpesvirus 1 (BoHV-1) is unique in its ability to target TAP for proteasomal degradation following conformational arrest by the UL49.5 gene product. The exact mechanism of TAP removal still requires elucidation. For this purpose, a TAP-GFP (green fluorescent protein) fusion protein is instrumental, yet GFP-tagging may affect UL49.5-induced degradation. Therefore, we constructed a series of TAP-GFP variants using various linkers to obtain an optimal cellular fluorescent TAP platform. Mel JuSo (MJS) cells with CRISPR/Cas9 TAP1 or TAP2 knockouts were reconstituted with TAP-GFP constructs. Our results point towards a critical role of GFP localization on fluorescent properties of the fusion proteins and, in concert with the type of a linker, on the susceptibility to virally-induced inhibition and degradation. The fluorescent TAP platform was also used to re-evaluate TAP stability in the presence of other known viral TAP inhibitors, among which only UL49.5 was able to reduce TAP levels. Finally, we provide evidence that BoHV-1 UL49.5-induced TAP removal is p97-dependent, which indicates its degradation via endoplasmic reticulum-associated degradation (ERAD).
|Journal series||Cells, ISSN 2073-4409, e-ISSN 2073-4409, (N/A 140 pkt)|
|Publication size in sheets||0.95|
|Keywords in English||TAP-GFP, fluorescent TAP platform, antigen presentation, MHC I, immune evasion, BoHV-1 UL49.5|
|License||Journal (articles only); published final; ; with publication|
|Score||= 140.0, 05-03-2020, ArticleFromJournal|
|Publication indicators||= 0; : 2017 = 1.344; : 2017 = 4.829 (2)|
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