Transcriptional regulation of the metazoan stress protein response.

This review provides an updated account of the regulation of the metazoan stress protein response. Where indicated, observations made with yeasts are also included. However, a discussion of the plant stress protein response is intentionally omitted (for a review, see 1). The stress protein response, as discussed hereafter, is understood to relate to the response by virtually all cells to heat and other stressors that results in the induced expression of so-called heat shock or stress genes. The protein products of these genes localize largely to the cytoplasm, nucleus, or organelles. An analogous response controls the expression of related genes, whose products reside in the endoplasmic reticulum. The response, termed ER stress response or unfolded protein response, is mediated by a separate regulation system that is not discussed in this review. Note, however, that recent work suggests the existence of commonalities between the regulatory systems controlling the stress protein and ER stress responses (2).