[Heat shock induces simultaneous rearrangements of all known cytoskeletal filaments in normal interphase fibroblasts].

We studied the cytoskeleton heat shock response (CHSR) in normal interphase embryonic (NERF) and postnatal rat fibroblasts (NPRF) using fluorescent microscopy. Incubation of the cells at 43 degrees C resulted in reorganization of the cytoskeleton. CHSR in NERF and in NPRF were similar. Under heat shock, the bundles of actin filaments disassembled, microtubule morphology changed remarkably, and intermediate filaments collapsed around the nucleus. After 30-120 minutes at 43 degrees C, the cells were still capable of regaining the actin cytoskeleton after the temperature returned to normal (37 degrees C). Analysis of CHSR dynamics showed that rearrangements of different types of the cytoskeletal filaments proceeded simultaneously, and they were visible after 2-4 minutes. We believe that the cytoskeleton reorganization under heat shock can be of vital importance in cell protection against temperature stress. There are data about possible conjugation of CHSR with the rearrangement of the protein synthesizing system, which results in synthesis of heat shock proteins.