title: Autophagy regulates the stability of sialin, a lysosomal sialic acid transporter.
abstract: Macroautophagy plays a critical role in catabolizing cytosolic components via lysosomal degradation. Recent findings from our studies indicate that basal autophagy is required for the efficient lysosomal catabolism of sialyloligosaccharides, and that the downregulation of sialin, a lysosomal transporter of sialic acids can cause a significant delay in the cytosolic accumulation of such glycans. The findings reported herein show that the sialin protein level was increased when the autophagy process was inhibited. This effect appears to be specific to sialin, since the amount of LAMP1, another lysosomal membrane protein, remains constant under the same conditions. Our results suggest that autophagy may regulate the stability of sialin, and it could lead to the cytosolic accumulation of sialyloligosaccharides in autophagy-defective cells.
authors.affiliation: a Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology , RIKEN Global Research Cluster , Wako , Japan.
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Huang
authors.forename: Junichi
authors.initials: J
authors.lastname: Seino
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Haga
authors.forename: Tadashi
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001343:Autophagy / Q000235:genetics*; D000071187:Autophagy-Related Protein 5; D001692:Biological Transport; D002460:Cell Line; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D051907:Lysosomal Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000172:deficiency / Q000235:genetics; D009844:Oligosaccharides / Q000378:metabolism; D027361:Organic Anion Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055550:Protein Stability; D012794:Sialic Acids / Q000378:metabolism*; D015398:Signal Transduction; D027981:Symporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D000071187:Autophagy-Related Protein 5; D051907:Lysosomal Membrane Proteins; D008869:Microtubule-Associated Proteins; D009844:Oligosaccharides; D027361:Organic Anion Transporters; D012794:Sialic Acids; D027981:Symporters; C495773:Atg5 protein, mouse; C052255:Lamp1 protein, mouse; D052118:Lysosomal-Associated Membrane Protein 1; C421224:sialic acid transport proteins; C016735:sialooligosaccharides
keywords: Atg5; autophagy; lysosome; sialin