Publikationsdatenbank

The role of the tyrosine-based sorting signals of the ORF3a protein of SARS-CoV-2 in intracellular trafficking and pathogenesis (2025)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Stephens, Edward B.

Kunec, Dusan (WE 5)

Henke, Wyatt

Vidal, Ricardo Martin (WE 5)

Greishaber, Brandon

Saud, Rabina

Kalamvoki, Maria

Singh, Gagandeep

Kafle, Sujan

Trujillo, Jessie D.

Ferreyra, Franco Matias

Morozov, Igor

Richt, Juergen A.

Quelle

Viruses

Bandzählung: 17

Heftzählung: 4

Seiten: 522

ISSN: 1999-4915

Sprache

Englisch

Verweise

URL (Volltext): https://www.mdpi.com/1999-4915/17/4/522

DOI: 10.3390/v17040522

Pubmed: 40284965

Kontakt

Institut für Virologie

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51833
virologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The open reading frame 3a (ORF3a) is a protein important to the pathogenicity of SARS-CoV-2. The cytoplasmic domain of ORF3a has three canonical tyrosine-based sorting signals (160YNSV163, 211YYQL213, and 233YNKI236), and a previous study has indicated that mutation of the 160YNSV163 motif abrogated plasma membrane expression and inhibited ORF3a-induced apoptosis. Here, we have systematically removed all three tyrosine-based motifs and assessed the importance of each motif or combination of motifs in trafficking to the cell surface. Our results indicate that the 160YNSV163 motif alone was insufficient for ORF3a cell-surface trafficking, while the 211YYQL213 motif was the most important. Additionally, an ORF3a with all three YxxΦ motifs disrupted (ORF3a-[ΔYxxΦ]) was not transported to the cell surface, and LysoIP studies indicate that ORF3a but not ORF3a-[ΔYxxΦ] was present in late endosome/lysosome fractions. A growth-curve analysis of different SARS-CoV-2 viruses expressing the different mutant ORF3a proteins revealed no significant differences in virus replication. Finally, the inoculation of K18hACE-2 mice indicated that the SARS-CoV-2 lacking the three YxxΦ motifs was less pathogenic than the unmodified SARS-CoV-2. These results indicate that the tyrosine motifs of ORF3a contribute to cell-surface expression and SARS-CoV-2 pathogenesis.