Millisecond dynamics of an unlabeled amino acid transporter.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33024106.
- Also identified by DOI 10.1038/s41467-020-18811-z and PMC identifier 7538599.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Excitatory amino acid transporters (EAATs) are important in many physiological processes and crucial for the removal of excitatory amino acids from the synaptic cleft. Here, we develop and apply high-speed atomic force microscopy line-scanning (HS-AFM-LS) combined with automated state assignment and transition analysis for the determination of transport dynamics of unlabeled membrane-reconstituted Glt<sub>Ph</sub>, a prokaryotic EAAT homologue, with millisecond temporal resolution. We find that Glt<sub>Ph</sub> transporters can operate much faster than previously reported, with state dwell-times in the 50 ms range, and report the kinetics of an intermediate transport state with height between the outward- and inward-facing states. Transport domains stochastically probe transmembrane motion, and reversible unsuccessful excursions to the intermediate state occur. The presented approach and analysis methodology are generally applicable to study transporter kinetics at system-relevant temporal resolution.
Medical subject headings
- Amino Acid Transport Systems
- Image Processing, Computer-Assisted
- Microscopy, Atomic Force