Work

PI(3,4,5)P3-mediated Cdc42 activation regulates macrophage podosome assembly

Year: 2025

Type: article

Abstract: Podosomes are adhesion structures with densely-polymerized F-actin. While PI(3,4,5)P3 and Cdc42-GTP are known factors to trigger WASP-mediated actin polymerization at the macrophage podosome, their causal mechanism to activate WASP remains unclear. Here, we demonstrate that spatially elevated Cdc42-GTP is a downstream effector of local PI(3,4,5)P3 production at the podosome. We further examine the expression and distribution of 19 Cdc42 guanine exchange factors (GEFs) and identify VAV1 as the key PI(3,4,5)P3-dependent Cdc42 GEF. VAV1 is spatially enriched at the macrophage podosome, and the association of VAV1 with the membrane plays a critical role in upregulating its GEF activity. Reintroduction of wildtype VAV1, rather than the PI(3,4,5)P3-binding deficient or catalytically dead mutants restores the matrix degradation and chemotactic migration of VAV1-knockdown macrophage. Thus, the biogenesis of PI(3,4,5)P3 acts as an upstream signal to locally recruit VAV1 and in turn triggers the guanine nucleotide exchange of Cdc42. Elevated levels of Cdc42-GTP then promote WASP-mediated podosome assembly and macrophage chemotaxis.

Source: Cellular and Molecular Life Sciences

DOI: 10.1007/s00018-025-05664-2

Authors: Yaoyue Qi, Cheng-han Yu

Institution: University of Hong Kong

Language: English

Topic: Protein Kinase Regulation and GTPase Signaling

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $4,290

Funder: Research Grants Council, University Grants Committee