title: Glycosylation affects the stability and subcellular distribution of human PAT1 protein.
abstract: The amino acid transporter PAT1 is typically expressed on the lysosome and plasma membranes in various human tissues. Glycosylation has been shown to be critical for the cell surface expression of PAT1, but not for its stability, in Xenopus oocytes. Here, we report that the glycosylation-deficient mutant of PAT1 (PAT13NQ) is unstable and is degraded mainly via the endoplasmic reticulum-associated degradation pathway in HEK293 cells. Interestingly, PAT13NQbinds preferentially to the plasma membrane rather than to the lysosome. Consistent with this altered distribution, overexpression of PAT13NQfails to inhibit the mechanistic target of rapamycin complex 1 (mTORC1). Our data suggest that glycosylation affects the stability and localization of PAT1 in HEK293 cells and the subcellular distribution of PAT1 is a factor affecting mTORC1 activity.
authors.affiliation: Key Laboratory of Animal Biotechnology, College of Veterinary Medicine, The Ministry of Agriculture, Northwest Agriculture & Forest University, Yangling, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Luo
authors.affiliation: Key Laboratory of Animal Biotechnology, College of Veterinary Medicine, The Ministry of Agriculture, Northwest Agriculture & Forest University, Yangling, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Animal Biotechnology, College of Veterinary Medicine, The Ministry of Agriculture, Northwest Agriculture & Forest University, Yangling, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ji
authors.affiliation: Key Laboratory of Animal Biotechnology, College of Veterinary Medicine, The Ministry of Agriculture, Northwest Agriculture & Forest University, Yangling, China.
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Animal Biotechnology, College of Veterinary Medicine, The Ministry of Agriculture, Northwest Agriculture & Forest University, Yangling, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Key Laboratory of Animal Biotechnology, College of Veterinary Medicine, The Ministry of Agriculture, Northwest Agriculture & Forest University, Yangling, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism*; D001216:Asparagine / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism*; D060746:Endoplasmic Reticulum-Associated Degradation / Q000235:genetics; D005973:Glutamine / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D000076222:Mechanistic Target of Rapamycin Complex 1; D046912:Multiprotein Complexes / Q000378:metabolism; D020125:Mutation, Missense; D055550:Protein Stability; D027981:Symporters / Q000235:genetics / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D026905:Amino Acid Transport Systems; D046912:Multiprotein Complexes; C475905:SLC36A1 protein, human; D027981:Symporters; D005973:Glutamine; D049452:Green Fluorescent Proteins; D001216:Asparagine; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases
keywords: PAT1; glycosylation; lysosome; mTORC1; stability