Cellular adaptation in response to heat exposure. Heat shock leads to aggregation of misfolded proteins (black) in the cytosol and the nucleus. The endoplasmic reticulum and the Golgi complex (dark blue) are fragmented and disassembled. Mitochondria (pink) and lysosomes (white) decrease in number and their integrity is compromised. Membraneless assemblies are formed in the cytosol (stress granules, green) and in the nucleus (transcriptional condensates, yellow). Heat stress also induces structural damage, as demonstrated by reorganization of actin filaments into stress fibers (purple) and rearrangement of other cytoskeletal components (data not shown). The plasma membrane morphology is altered and there is an increase in membrane permeability.
