Related Experiment Video
Updated: Jun 16, 2026

Real-time Imaging of Axonal Transport of Quantum Dot-labeled BDNF in Primary Neurons
Published on: September 15, 2014
Delivery of GABAARs to synapses is mediated by HAP1-KIF5 and disrupted by mutant huntingtin
Alison E Twelvetrees1, Eunice Y Yuen, I Lorena Arancibia-Carcamo
1Department of Neuroscience, Physiology, and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
Abstract:
The density of GABA(A) receptors (GABA(A)Rs) at synapses regulates brain excitability, and altered inhibition may contribute to Huntington's disease, which is caused by a polyglutamine repeat in the protein huntingtin. However, the machinery that delivers GABA(A)Rs to synapses is unknown. We demonstrate that GABA(A)Rs are trafficked to synapses by the kinesin family motor protein 5 (KIF5). We identify the adaptor linking the receptors to KIF5 as the huntingtin-associated protein 1 (HAP1). Disrupting the HAP1-KIF5 complex decreases synaptic GABA(A)R number and reduces the amplitude of inhibitory postsynaptic currents. When huntingtin is mutated, as in Huntington's disease, GABA(A)R transport and inhibitory synaptic currents are reduced. Thus, HAP1-KIF5-dependent GABA(A)R trafficking is a fundamental mechanism controlling the strength of synaptic inhibition in the brain. Its disruption by mutant huntingtin may explain some of the defects in brain information processing occurring in Huntington's disease and provides a molecular target for therapeutic approaches.
Related Concept Videos
Huntington Disease l: Introduction
Rab Cascades
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Hedgehog Signaling Pathway
Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
Ligand-Gated Ion Channel Receptor: Gating Mechanism

