Processing of N-glycans in the ER and Golgi influences the production of surface sialylated glycoRNA

Abstract

Glycoconjugates, including glycans on proteins and lipids, have obtained significant attention due to their critical roles in both intracellular and intercellular biological functions and processes. Notably, recent discoveries have revealed the presence of glycosylated RNAs (glycoRNAs) on cell surfaces. Despite the well-characterized roles of RNA modifications, RNA glycosylation remains relatively unexplored. In this study, we investigate the relationship between N-glycosylation and RNA glycosylation. Using a recombinant Siglec11-Fc as a probe, we detected surface sialylated glycoRNAs in human cell lines and identified their dependency on the catalytic isoforms of the oligosaccharyltransferase (OST) complex, implicating STT3A-dependent protein glycosylation as a predominant contributor for affecting indirect generation of glycoRNAs. Additionally, perturbations in N-glycan biosynthesis pathways or changes in N-glycan structure impact surface sialylated glycoRNA levels, indicating a regulatory role of glycan metabolic pathways in RNA glycosylation. Together, our results underscore the intricate relationship between protein N-glycosylation and processing and RNA biology.

Keywords: N-glycosylation; Oligosaccharyltransferase; Sialic acid; Siglec11; glycoRNA.