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Biological activities of HAP46/BAG‐1
Author(s) -
Gehring Ulrich
Publication year - 2004
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/sj.embor.7400083
Subject(s) - biology , computational biology
HAP46/BAG‐1M and its isoforms affect the protein‐folding activities of mammalian HSP70 chaperones. They interact with the ATP‐binding domain of HSP70 or HSC70, leaving the substrate‐binding site available for further interactions. Trimeric complexes can therefore form with, for example, transcription factors. Moreover, HAP46/BAG‐1M and the larger isoform HAP50/BAG‐1L bind to DNA non‐specifically and enhance transcription in vitro and upon overexpression in intact cells. These factors are linked to positive effects on cell proliferation and survival. This review focuses on DNA‐binding activity and transcriptional stimulation by HAP46/BAG‐1M, and presents a molecular model for the underlying mechanism. It is proposed that transcription factors are recruited into complexes with HAP46/BAG‐1M or HAP50/BAG‐1L through HSP70/HSC70 and that response‐element‐bound complexes that contain HAP46/BAG‐1M and/or HAP50/BAG‐1L along with HSP70s target and affect the basal transcription machinery.