Related Experiment Video
Updated: Jul 13, 2026

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
Published on: March 9, 2012
p38alpha MAPK can positively or negatively regulate Rac-1 activity depending on the presence of serum
Susana Zuluaga1, Alvaro Gutiérrez-Uzquiza, Paloma Bragado
1Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, UCM, Ciudad Universitaria, 28040 Madrid, Spain.
Abstract:
The small GTP-ase Rac-1 can trigger p38 MAPK activation and, in turn, p38alpha can regulate signalling pathways that potentially impinge on Rac-1 activity. We have investigated the cross-talk between p38alpha and Rac-1 and found that p38alpha regulates the association between Rac-1 and caveolin-1 in serum-deprived cardiomyocytes. This interaction depends on cell attachment and correlates with higher levels of active Rac-1. Actin organization might regulate the formation of Rac-1-caveolin-1 complexes. In contrast, the Rac-1-caveolin-1 interaction is almost undetectable in the presence of serum, where Rac-1 activity is negatively regulated by p38alpha. Our results indicate that p38alpha can differentially contribute to Rac-1 activation depending on the presence of serum.
More Related Videos
Related Concept Videos
MAPK Signaling Cascades
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
The JAK-STAT Signaling Pathway
The Ras Gene
Ras is a superfamily...
Cell Polarization by Rho Proteins
