Work

Investigation of the allosteric coupling mechanism in a glutamate transporter homolog via unnatural amino acid mutagenesis

Year: 2019

Type: article

Abstract: Significance Glutamate transporters harness ionic gradients for the concentrative uptake of glutamate. Normal function of glutamate transporters is required for rapid removal of glutamate from the synaptic space, which is required for efficient neurotransmission and preventing excitotoxicity. A key question in glutamate transporters is the mechanism by which the ionic gradient is coupled to glutamate uptake. Previous studies have proposed a role for hairpin-2 (HP2) in this coupling mechanism. Here, we use unnatural amino-acid mutagenesis to develop a fluorescence assay for HP2 movement in the archaeal homolog, Glt Ph . Using this assay, we show how key residues in the substrate binding site modulate movement of HP2 and thereby identify the sequence of events involved in the coupled binding of sodium and substrate.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.1907852116

Authors: Erika A. Riederer, Francis I. Valiyaveetil

Institution: Oregon Health & Science University

Language: English

Topic: Amino Acid Enzymes and Metabolism

Subfield: Biochemistry

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: American Heart Association, National Institutes of Health, National Institute of General Medical Sciences, National Institute of Neurological Disorders and Stroke

Awards: Probing functional mechanisms in K+ channels using unnatural mutagenesis, Using unnatural amino acid mutagenesis to probe a glutamate transporter homolog, The structural dynamics of a glutamate transporter homologue, Unnatural mutagenesis to probe the transport mechanism of a glutamate transporter homolog