Building Up and Tearing Down

Abstract

Hormone induction can stop very rapidly once the hormone is removed. What is the mechanism for this rapid cessation of transcription? Freeman and Yamamoto (p. 2232) show that molecular chaperones can disassemble the large multisubunit complexes that form on promoters and that induce gene expression. The authors used chimeric constructs to increase the local concentration of the chaperones in vivo and showed that when the chaperone p23 is localized to a promoter region, transcription is down-regulated. Hence, chaperones may play dual roles in the assembly and disassembly of transcription complexes. B. C. Freeman, K. R. Yamamoto, Disassembly of transcriptional regulatory complexes by molecular chaperones.Science 296, 2232-2235 (2002). [Abstract] [Full Text]