AlphaB-crystallin interacts with intermediate filaments in response to stress.
The small heat shock protein alphaB-crystallin interacts with intermediate filament proteins. Using a co-sedimentation assay, we showed that in vitro binding of alphaB-crystallin to peripherin and vimentin was temperature-dependent. Specifically, a synthetic peptide representing the first ten residues of alphaB-crystallin was involved in this interaction. When cells were submitted to different stress conditions such as serum starvation, hypertonic stress, or heat shock, we observed a dynamic reorganisation of the intermediate filament network, and concomitant recruitment of alphaB-crystallins on intermediate filament proteins. Under normal conditions alphaB-crystallin was extracted from cells by detergent. In stressed cells, alphaB-crystallin colocalised with intermediate filament proteins, and became resistant to detergent extraction. The intracellular state of alphaB-crystallin seemed to correlate directly with the remodelling of the intermediate filament network in response to stress. This suggested that alphaB-crystallin functions as a molecular chaperone for intermediate filament proteins.
Djabali
K
K
Faculté de Médecine, Pitié-Salpêtrière, CNRS-URA 2115, Cytosquelette et Développement, Paris, France.
de Néchaud
B
B
Landon
F
F
Portier
M M
MM
D016475:3T3 Cells; D000818:Animals; D003459:Crystallins / Q000502:physiology*; D016895:Culture Media, Serum-Free; D018882:Heat Stress Disorders; D006360:Heat-Shock Proteins / Q000502:physiology*; D006982:Hypertonic Solutions; D007382:Intermediate Filaments / Q000502:physiology*; D051379:Mice; D018832:Molecular Chaperones / Q000502:physiology; D014746:Vimentin / Q000502:physiology
D003459:Crystallins; D016895:Culture Media, Serum-Free; D006360:Heat-Shock Proteins; D006982:Hypertonic Solutions; D018832:Molecular Chaperones; D014746:Vimentin