Guanine Nucleotide Exchange Factors in Cell Signaling

Guanine nucleotide exchange factors (GEFs) are pivotal regulators of small GTPases, catalysing the exchange of GDP for GTP to switch these molecular switches from an inactive to an active state. Through this mechanism, GEFs control a myriad of cellular processes including cytoskeletal remodelling, cell migration, proliferation, vesicle trafficking and gene expression. The largest class, the Dbl family, comprises over 70 members defined by a conserved Dbl homology (DH) domain for catalytic activity and an adjoining pleckstrin homology (PH) domain that mediates membrane association and interaction with phosphoinositides. Other families, such as the Dock proteins, use distinct domains to achieve specificity and regulation. GEF activity is tightly regulated by autoinhibitory intramolecular contacts, phosphorylation events and binding to lipid second messengers or G protein βγ subunits, ensuring spatially and temporally precise activation of Rho, Rac and Cdc42 GTPases. Dysregulation of GEFs has been implicated in pathological states including cancer, vascular inflammation and immune disorders, making them attractive targets for therapeutic intervention and biomarker development.

Research from Nature Portfolio

Foundational work has demonstrated that restricting GEF catalytic domains to the plasma membrane is sufficient to generate local RhoA activation and induce actin polymerisation. Using a FRET-based biosensor for RhoA nucleotide loading, researchers showed that membrane‐anchored p63RhoGEF responds to endogenous GPCR signals with rapid and spatially confined RhoA activation. Synthetic recruitment of the DH domain to the cell periphery, bypassing other regulatory regions, recapitulated physiological actin assembly and morphological change. These findings underscore the importance of membrane microdomain localisation in GEF‐mediated signalling and provide a minimal synthetic system for dissecting spatiotemporal control of GTPase activation.

Guanine Nucleotide Exchange Factors in Cell Signaling publication trend

The graph below shows the total number of articles in guanine nucleotide exchange factors in cell signaling across all publications each year (not limited to Nature Index journals).

Technical terms

Guanine nucleotide exchange factor (GEF): A protein that activates small GTPases by promoting the release of bound GDP to allow GTP binding.

Small GTPase: A monomeric G protein that cycles between an inactive GDP-bound state and an active GTP-bound state to regulate intracellular signalling.

Dbl homology (DH) domain: A conserved catalytic module within Dbl family GEFs responsible for mediating nucleotide exchange on Rho GTPases.

Pleckstrin homology (PH) domain: A lipid-binding domain that directs GEFs to specific membrane locations via interaction with phosphoinositides such as PIP₃.

Phosphatidylinositol (3,4,5)-trisphosphate (PIP₃): A membrane phospholipid generated by PI3K that recruits PH-domain proteins to the plasma membrane to regulate signal transduction.

References

1. PREX2 contributes to radiation resistance by inhibiting radiotherapy-induced tumor immunogenicity via cGAS/STING/IFNs pathway in colorectal cancer. BMC Medicine (2024).
2. Rhogef17: A novel target for endothelial barrier function. Biomedicine & Pharmacotherapy (2023).
3. Structural and dynamic changes in P-Rex1 upon activation by PIP3 and inhibition by IP4. eLife (2024).
4. Plasma membrane restricted RhoGEF activity is sufficient for RhoA-mediated actin polymerization. Scientific Reports (2015).