Direct visualization of glutamate transporter elevator mechanism by high-speed AFM Academic Article uri icon

Overview

MeSH Major

  • Amino Acid Transport Systems
  • Aspartic Acid
  • Pyrococcus horikoshii
  • Sodium

abstract

  • Glutamate transporters are essential for recovery of the neurotransmitter glutamate from the synaptic cleft. Crystal structures in the outward- and inward-facing conformations of a glutamate transporter homolog from archaebacterium Pyrococcus horikoshii, sodium/aspartate symporter GltPh, suggested the molecular basis of the transporter cycle. However, dynamic studies of the transport mechanism have been sparse and indirect. Here we present high-speed atomic force microscopy (HS-AFM) observations of membrane-reconstituted GltPh at work. HS-AFM movies provide unprecedented real-space and real-time visualization of the transport dynamics. Our results show transport mediated by large amplitude 1.85-nm "elevator" movements of the transport domains consistent with previous crystallographic and spectroscopic studies. Elevator dynamics occur in the absence and presence of sodium ions and aspartate, but stall in sodium alone, providing a direct visualization of the ion and substrate symport mechanism. We show unambiguously that individual protomers within the trimeric transporter function fully independently.

publication date

  • February 14, 2017

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC5320997

Digital Object Identifier (DOI)

  • 10.1073/pnas.1616413114

PubMed ID

  • 28137870

Additional Document Info

start page

  • 1584

end page

  • 1588

volume

  • 114

number

  • 7