Functional heterodimeric amino acid transporters lacking cysteine residues involved in disulfide bond
| Autor: | Benjamin Spindler, François Verrey, Patrick J. Skelly, Jan Loffing, Charles B. Shoemaker, Rahel Pfeiffer |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
CD98
Amino Acid Transport Systems Protein Conformation Fusion Regulatory Protein-1 Biophysics Immunoglobulin light chain Biochemistry Structure-Activity Relationship Xenopus laevis 03 medical and health sciences Residue (chemistry) 0302 clinical medicine Structural Biology Genetics Animals Cysteine Disulfides Amino acid transporter Site-directed mutagenesis Molecular Biology 030304 developmental biology chemistry.chemical_classification 0303 health sciences Disulfide bond biology Cell Biology Precipitin Tests Amino acid chemistry Mutagenesis Site-Directed Oocytes biology.protein Xenopus oocyte Carrier Proteins Dimerization 030217 neurology & neurosurgery Site directed mutagenesis |
| Zdroj: | FEBS Letters. (1-2):157-162 |
| ISSN: | 0014-5793 |
| DOI: | 10.1016/S0014-5793(98)01359-3 |
| Popis: | The protein mediating system L amino acid transport, AmAT-L, is a disulfide-linked heterodimer of a permease-related light chain (AmAT-L-lc) and the type II glycoprotein 4F2hc/CD98. The Schistosoma mansoni protein SPRM1 also heterodimerizes with h4F2hc, inducing amino acid transport with different specificity. In this study, we show that the disulfide bond is formed by heavy chain C109 with a Cys residue located in the second putative extracellular loop of the multi-transmembrane domain light chain (C164 and C137 for XAmAT-L-lc and SPRM1, respectively). The non-covalent interaction of Cys-mutant subunits is not sufficient to allow coimmunoprecipitation, but cell surface expression of the light chains is maintained to a large extent. The non-covalently linked transporters display the same transport characteristics as disulfide bound heterodimers, but the maximal transport rates are reduced by 30–80%. |
| Databáze: | OpenAIRE |
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