Related Experiment Video
Updated: Jul 12, 2026

Detection of In Situ Protein-protein Complexes at the Drosophila Larval Neuromuscular Junction Using Proximity Ligation Assay
Published on: January 20, 2015
Regulation of postsynaptic structure and protein localization by the Rho-type guanine nucleotide exchange factor dPix
D Parnas1, A P Haghighi, R D Fetter
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
Abstract:
Mutations in dpix were recovered from a large-scale screen in Drosophila for genes that control synaptic structure. dpix encodes dPix, a Rho-type guanine nucleotide exchange factor (RtGEF) homologous to mammalian Pix. Here we show that dPix plays a major role in regulating postsynaptic structure and protein localization at the Drosophila glutamatergic neuromuscular junction. dpix mutations lead to decreased synaptic levels of the PDZ protein Dlg, the cell adhesion molecule Fas II, and the glutamate receptor subunit GluRIIA, and to a complete reduction of the serine/threonine kinase Pak and the subsynaptic reticulum. The electrophysiology of these mutant synapses is nearly normal. Many, but not all, dpix defects are mediated through dPak, a member of the family of Cdc42/Rac1-activated kinases. Thus, a Rho-type GEF and Rho-type effector kinase regulate postsynaptic structure.
More Related Videos
Related Concept Videos
GTPases and their Regulation
Large G-proteins, also known...
Regulation of Nuclear Protein Sorting
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...
GTPases and their Regulation
Large G-proteins, also known...
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
IP3/DAG Signaling Pathway

