|Vol. 3 (No. 4), pp. 111-141, 2010||doi:10.5047/absm.2010.00304.0111|
Michiaki Yamashita, Takeshi Yabu and Nobuhiko Ojima
National Research Institute of Fisheries Science 2-12-4 Fukuura, Yokohama 236-8648, Japan
(Received on February 2, 2010; Accepted on August 17, 2010; Published online on December 29, 2010)
Abstract: Stress proteins (heat-shock proteins, HSPs), which comprise an evolutionally well-conserved protein family, are induced in response to a variety of stress conditions and metabolic insults. When cells are subjected to sudden environmental changes, stress proteins are induced and play a central role in cellular homeostasis. A response to sudden adverse environmental changes is referred to as the heat-shock or stress response and is accompanied by a rapid increase in the synthesis of stress proteins. Given the importance of stress proteins in thermal adaptation at the cellular level, we have studied the expression, regulation, and protective functions of the members of the HSP70 stress protein family under normal and stress conditions in a variety of fish species. HSP70/heat-shock cognate protein-70 (HSC70) plays essential roles in the receptor complex formation and activation of Activin/Nodal/transforming growth factor-β and bone morphogenetic protein receptors and facilitates Nodal signaling. In addition, chaperone-mediated autophagy assisted by HSP70/heat-shock cognate (HSC)70 may be responsible for the stress responses in fish cells. HSP70 and HSC70 translocated into the lysosomes were found to accelerate protein degradation and catabolism under both stressed and normal conditions.
Keywords: activin, development, HSP70, HSC70, heat-shock transcription factor HSF, molecular chaperone, rainbow trout, Nodal, stress protein TGF-β, transgenic zebrafish
[Full text] (PDF 6.3 MB)