Cysteine 467 of the ASCT2 Amino Acid Transporter Is a Molecular Determinant of the Antiport Mechanism.

ABSTRACT: The plasma membrane transporter ASCT2 is a well-known Na+-dependent obligatory antiporter of neutral amino acids. The crucial role of the residue C467 in the recognition and binding of the ASCT2 substrate glutamine, has been highlighted by structure/function relationship studies. The reconstitution in proteoliposomes of the human ASCT2 produced in P. pastoris is here employed to unveil another role of the C467 residue in the transport reaction. Indeed, the site-directed mutant C467A displayed a novel property of the transporter, i.e., the ability of mediating a low but measurable unidirectional transport of [3H]-glutamine. This reaction conforms to the main features of the ASCT2-mediated transport, namely the Na+-dependence, the pH dependence, the stimulation by cholesterol included in the

SUBMITTER: Scalise M 

PROVIDER: S-EPMC8835248 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature