Stt3a, the catalytic subunit of oligosaccharyltransferase (OST), is crucial for N-glycosylation, a process that attaches oligosaccharides to proteins. N-glycosylation via Stt3a is involved in numerous biological processes, and genetic models such as knockout (KO) mouse models can help reveal its functions [3,4,5,6].

In oncolytic virus M1, Stt3a-mediated N-glycosylation of the virus envelope is essential for efficient receptor binding and oncolysis, and Stt3a expression in tumor cells is positively correlated with M1-induced oncolysis, indicating its potential as a biomarker [1]. In hepatocellular carcinoma, GMPS promotes PD-L1 glycosylation modification in a Stt3a-dependent manner, driving tumor immune evasion [2]. In lung adenocarcinoma, high Stt3a expression is associated with poor overall survival, and its knockout or inhibition suppresses tumor cell proliferation, migration, invasion, and tumor growth in vivo, likely through the MAPK and PI3K/AKT signaling pathways [4]. For herpes simplex virus 1, N-glycosylation of some envelope proteins depends on Stt3a-OST, and targeting Stt3a-OST with NGI-1 can cause virus dysfunction in certain cell types [3].

In summary, Stt3a-mediated N-glycosylation is vital in various biological processes and disease conditions. KO/CKO mouse models have contributed to understanding its role in cancer and viral-related diseases, highlighting its potential as a therapeutic target and biomarker in oncology and antiviral research.