Expression of human HSP70 during the synthetic phase of the cell cycle.

AUTOR(ES)

Milarski, K L

RESUMO

Expression of the major heat shock and stress-induced protein, HSP70, is under complex regulatory control in human cells. In addition to being induced by physiological stress such as heat shock or transition metals, the HSP70 gene is induced by serum stimulation and immortalizing products of the adenovirus E1A 13S and polyoma large tumor antigen genes. Here we show that expression of the human HSP70 gene is tightly regulated during the cell cycle. Using selective mitotic detachment, a noninductive method to obtain synchronous populations of HeLa cells, we show that levels of HSP70 mRNA rapidly increase 10- to 15-fold upon entry into S phase and decline by late S and G2. A transient increase in HSP70 synthesis is detected during early S phase. The subcellular localization of HSP70 varies throughout the cell cycle; the protein is diffusely distributed in the nucleus and cytoplasm in G1, localized in the nucleus in S, and again diffusely distributed in G2 cells. We suggest that the temporal pattern of HSP70 expression during S phase, the nuclear localization, and activation by trans-acting immortalizing proteins indicate a role for HSP70 in the nucleus of replicating cells.

Documentos Relacionados

• Hsp70 expression and function during embryogenesis
• Induction of cellular hsp70 expression by human cytomegalovirus.
• Gene expression of human DNA polymerase alpha during cell proliferation and the cell cycle.
• Cell cycle control of the human HSP70 gene: implications for the role of a cellular E1A-like function.
• Ectoine from halophilic microorganisms induces the expression of hsp70 and hsp70B′ in human keratinocytes modulating the proinflammatory response