Modulation of actin dynamics during stress and physiological stimulation by a signaling pathway involving p38 MAP kinase and heat-shock protein 27.
HSP27, like other proteins of the heat-shock protein family, accumulates to high levels after exposure of cells to a short period of hyperthermia and contributes to the development of a transient state of thermoresistance. In vitro, HSP27 behaves as an actin cap-binding protein and can inhibit actin polymerization. In vivo, the protective function of HSP27 is exerted mainly at the level of the microfilaments and appears as an extension of a normal function of the protein. This function is regulated by phosphorylation in a mitogen- and stress-sensitive signaling pathway involving the newly characterized p38 MAP kinase. The phosphorylation-modulated function of HSP27 can contribute to agonist-induced reorganization of the actin cytoskeleton and, in the case of stress activation, provides an actin-based adaptive response of cells to the new environmental conditions.
Landry
J
J
Centre de recherche en cancérologie de l'Université Laval, L'Hôtel-Dieu de Québec, Canada.
Huot
J
J
D000199:Actins / Q000378:metabolism*; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000502:physiology*; D006801:Humans; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D011485:Protein Binding; D015398:Signal Transduction / Q000502:physiology*; D013312:Stress, Physiological / Q000378:metabolism / Q000503:physiopathology*; D048051:p38 Mitogen-Activated Protein Kinases
D000199:Actins; D006360:Heat-Shock Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases