Guanine Nucleotide Exchange Factors in Cell Motility

Guanine nucleotide exchange factors (GEFs) orchestrate the activation of Rho family GTPases, notably Rac1 and Cdc42, driving the dynamic remodelling of the actin cytoskeleton that underlies cell migration. Two principal GEF families, the Dbl-like proteins and the atypical DOCK (dedicator of cytokinesis) proteins, employ distinct catalytic domains to facilitate GDP–GTP exchange. DOCK family GEFs engage scaffolding partners such as ELMO (engulfment and cell motility) proteins to localise and regulate Rac1 activation at the leading edge, promoting lamellipodia and filopodia formation. These protrusive structures generate traction forces for directional movement in processes ranging from embryonic morphogenesis to wound healing and immune surveillance. Dysregulation of GEF activity contributes to pathological states including metastatic invasion, chronic inflammation and neurodegeneration. Recent advances in structural biology and chemical biology have elucidated the mechanisms of auto-inhibition, partner switching and small-molecule modulation of GEFs, revealing new avenues for therapeutic intervention in diseases driven by aberrant cell motility.

Research from Nature Portfolio

Computational nanobody design has been applied to the Ras-binding domain of ELMO1, yielding high-affinity binders that sterically inhibit the interaction with RhoG. Optimisation through structure–activity guided mutagenesis produced variants that disrupt cytoskeletal activation, highlighting a novel strategy to impede metastatic cell migration by targeting GEF–effector interfaces.

Cryo-electron microscopy of the DOCK2–ELMO1 complex, both in its auto-inhibited state and in an open assembly with Rac1, has revealed the conformational switch that unmasks the DHR2 catalytic site. These structures uncover how upstream effectors and phosphorylation events destabilise the closed conformation, providing a molecular blueprint for selective modulation of Rac1 activation.

Guanine Nucleotide Exchange Factors in Cell Motility publication trend

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

Technical terms

Guanine nucleotide exchange factor (GEF): Enzyme that activates small GTPases by catalysing the exchange of GDP for GTP.

Rho GTPases: Family of small GTP-binding proteins (including Rac1 and Cdc42) that regulate actin cytoskeleton dynamics.

DOCK homology region 2 (DHR2): Catalytic domain of DOCK family GEFs responsible for nucleotide exchange on Rac and Cdc42.

ELMO proteins: Scaffolding partners of DOCK GEFs that regulate their localisation and activation state.

Cryo-electron microscopy: Structural technique that images flash-frozen specimens to determine high-resolution conformations of macromolecular assemblies.

Nanobody: Single-domain antibody fragment derived from camelid antibodies, used for high-affinity binding to specific protein targets.

Lamellipodia: Sheet-like actin filament networks at the leading edge of migrating cells that generate protrusive force.

Filopodia: Finger-like actin-rich protrusions that sense the microenvironment and guide directional migration.

References

1. Targeting Ras-binding domain of ELMO1 by computational nanobody design. Communications Biology (2023).
2. Structure of the DOCK2−ELMO1 complex provides insights into regulation of the auto-inhibited state. Nature Communications (2020).
3. Neuroprotection and axon regeneration by novel low-molecular-weight compounds through the modification of DOCK3 conformation. Cell Death Discovery (2023).
4. ELMO1 Deficiency Reduces Neutrophil Chemotaxis in Murine Peritonitis. International Journal of Molecular Sciences (2023).
5. CED-5/CED-12 (DOCK/ELMO) can promote and inhibit F-actin formation via distinct motifs that may target different GTPases. PLOS Genetics (2024).