Rac-Maninoff and Rho-Vel: The Symphony of Rho-GTPase Signaling at Excitatory Synapses

Authors

Joseph G Duman
Francisco A Blanco
Christopher A Cronkite
Qin Ru
Kelly C Erikson
Shalaka Mulherkar
Ali Bin Saifullah
Karen Firozi
Kimberley F Tolias

Publication Date

1-1-2022

Journal

Small GTPases

DOI

10.1080/21541248.2021.1885264

PMID

33955328

PMCID

PMC9707551

PubMedCentral® Posted Date

5-6-2021

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

Humans, rho GTP-Binding Proteins, Guanine Nucleotide Exchange Factors, Autism Spectrum Disorder, Synapses, Signal Transduction, Rac1, RhoA, Cdc42, LTP, LTD, NMDA receptor, AMPA receptor, dendritic spine

Abstract

Synaptic connections between neurons are essential for every facet of human cognition and are thus regulated with extreme precision. Rho-family GTPases, molecular switches that cycle between an active GTP-bound state and an inactive GDP-bound state, comprise a critical feature of synaptic regulation. Rho-GTPases are exquisitely controlled by an extensive suite of activators (GEFs) and inhibitors (GAPs and GDIs) and interact with many different signalling pathways to fulfill their roles in orchestrating the development, maintenance, and plasticity of excitatory synapses of the central nervous system. Among the mechanisms that control Rho-GTPase activity and signalling are cell surface receptors, GEF/GAP complexes that tightly regulate single Rho-GTPase dynamics, GEF/GAP and GEF/GEF functional complexes that coordinate multiple Rho-family GTPase activities, effector positive feedback loops, and mutual antagonism of opposing Rho-GTPase pathways. These complex regulatory mechanisms are employed by the cells of the nervous system in almost every step of development, and prominently figure into the processes of synaptic plasticity that underlie learning and memory. Finally, misregulation of Rho-GTPases plays critical roles in responses to neuronal injury, such as traumatic brain injury and neuropathic pain, and in neurodevelopmental and neurodegenerative disorders, including intellectual disability, autism spectrum disorder, schizophrenia, and Alzheimer's Disease. Thus, decoding the mechanisms of Rho-GTPase regulation and function at excitatory synapses has great potential for combatting many of the biggest current challenges in mental health.