{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Shi Q"],"funding":["NEI NIH HHS"],"pagination":["38086-38094"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC3207422"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["286(44)"],"pubmed_abstract":["Members of system N/A amino acid transporter (SNAT) family mediate transport of neutral amino acids, including l-alanine, l-glutamine, and l-histidine, across the plasma membrane and are involved in a variety of cellular functions. By using chemical labeling, glycosylation, immunofluorescence combined with molecular modeling approaches, we resolved the membrane topological structure of SNAT4, a transporter expressed predominantly in liver. To analyze the orientation using the chemical labeling and biotinylation approach, the \"Cys-null\" mutant of SNAT4 was first generated by mutating all five endogenous cysteine residues. Based on predicted topological structures, a single cysteine residue was introduced individually into all possible nontransmembrane domains of the Cys-null mutant. The cells expressing these mutants were labeled with N-biotinylaminoethyl methanethiosulfonate, a membrane-impermeable cysteine-directed reagent. We mapped the orientations of N- and C-terminal domains. There are three extracellular loop domains, and among them, the second loop domain is the largest that spans from amino acid residue ∼242 to ∼335. The orientation of this domain was further confirmed by the identification of two N-glycosylated residues, Asn-260 and Asn-264. Together, we showed that SNAT4 contains 10 transmembrane domains with extracellular N and C termini and a large N-glycosylated, extracellular loop domain. This is the first report concerning membrane topological structure of mammalian SNAT transporters, which will provide important implications for our understanding of structure-function of the members in this amino acid transporter family."],"journal":["The Journal of biological chemistry"],"pubmed_title":["Membrane topological structure of neutral system N/A amino acid transporter 4 (SNAT4) protein."],"pmcid":["PMC3207422"],"funding_grant_id":["R01 EY012085","R29 EY012085","EY12085"],"pubmed_authors":["Gu S","Padmanabhan R","Villegas CJ","Shi Q","Jiang JX"],"additional_accession":[]},"is_claimable":false,"name":"Membrane topological structure of neutral system N/A amino acid transporter 4 (SNAT4) protein.","description":"Members of system N/A amino acid transporter (SNAT) family mediate transport of neutral amino acids, including l-alanine, l-glutamine, and l-histidine, across the plasma membrane and are involved in a variety of cellular functions. By using chemical labeling, glycosylation, immunofluorescence combined with molecular modeling approaches, we resolved the membrane topological structure of SNAT4, a transporter expressed predominantly in liver. To analyze the orientation using the chemical labeling and biotinylation approach, the \"Cys-null\" mutant of SNAT4 was first generated by mutating all five endogenous cysteine residues. Based on predicted topological structures, a single cysteine residue was introduced individually into all possible nontransmembrane domains of the Cys-null mutant. The cells expressing these mutants were labeled with N-biotinylaminoethyl methanethiosulfonate, a membrane-impermeable cysteine-directed reagent. We mapped the orientations of N- and C-terminal domains. There are three extracellular loop domains, and among them, the second loop domain is the largest that spans from amino acid residue ∼242 to ∼335. The orientation of this domain was further confirmed by the identification of two N-glycosylated residues, Asn-260 and Asn-264. Together, we showed that SNAT4 contains 10 transmembrane domains with extracellular N and C termini and a large N-glycosylated, extracellular loop domain. This is the first report concerning membrane topological structure of mammalian SNAT transporters, which will provide important implications for our understanding of structure-function of the members in this amino acid transporter family.","dates":{"release":"2011-01-01T00:00:00Z","publication":"2011 Nov","modification":"2024-12-03T20:08:43.957Z","creation":"2019-03-27T00:45:38Z"},"accession":"S-EPMC3207422","cross_references":{"pubmed":["21917917"],"doi":["10.1074/jbc.M111.220277","10.1074/jbc.m111.220277"]}}