Regulatory role of the 90-kDa-heat-shock protein (Hsp90) and associated factors on gene expression

ERLEJMAN AG, LAGADARI M, TONEATTO J, PIWIEN-PILIPUK G, GALIGNIANA MD

BIOCHIMICA ET BIOPHYSICA ACTA, N. GENE STRUCTURE AND EXPRESSION

ELSEVIER

Lugar: Amsterdam; Año: 2014 vol. 1839 p. 71 - 87

0167-4781

The term molecular chaperone was first used to describe the ability of nucleoplasmin to prevent the aggregation of histones with DNA during the assembly of nucleosomes. Then, the name was also extended to those proteins that mediate the post-translational assembly of protein complexes protecting them from denaturation and aggregation. Hsp90 is a chaperone that represents the major soluble protein of the cell, but its role is to provide biological activity to properly folded client proteins with a preserved tertiary structure. Therefore, in contrast to most chaperones, Hsp90 functions as a delicate and refined sensor of protein function rather than a gross folding factor. Hsp90 is related to basic cell functions such as cytoplasmic transport of soluble factors, translocation of client proteins to organelles, and the regulation of the biological activity of a number of key signalling factors and other proteins such as protein kinases, steroid receptors, cell cycle regulators, transcription factors, etc. Growing number of evidences link the protective action of this chaperone to mechanisms related to posttranslational modifications of key soluble nuclear factors as well as histones. In this article, we discuss some aspects of the regulatory action of Hsp90 on transcriptional regulation and how this could have impacted the genetic assimilation of organisms.