2018 年 30 巻 176 号 p. E161-E167
Glycosylation is a major form of co-/post-translational modification associated with a variety of biological processes. Research in the field of glycobiology has elucidated details of glycan biosynthesis pathways as well as the diverse functions of glycans in biological processes. The detailed mechanisms of lysosomal degradation/turnover of glycans and the correlation between dysfunction of lysosomal enzymes involved in glycan degradation and lysosomal storage diseases are also well described. “Free” forms of glycans, unconjugated oligosaccharides designated “free N-glycans” (fNGs), continuously accumulate and undergo degradation in the cytosol. However, details regarding several steps in fNGs generation and degradation pathways as well as the biological significance of fNGs turnover remain to be elucidated. This article summarizes recent findings and the current state of knowledge regarding the detailed mechanisms and physiologic role of fNGs metabolism and discusses the diversity of fNGs structures and degradation pathways in eukaryotes.
