Heat-shock proteins classes

Aguas, A., Esaguy, N., Sunkel, C.E., Silva, M.T. (1990). Cross-reactivity and sequence homology between the 65 kilodalton mycobacterial heat shock protein and human lactoferrin, transferrin, and DR beta subsets of major histocompatibility complex class II molecules. Infect. Immun. 58, 1461-1470. 

Jinn TL, Chang PFL, Chen YM, Key JL, Lin CY. Tissue-type-specific-heat-shock response and immunolocalization of class 1 low-molecular-weight heat-shock proteins in soybean. Plant Physiol 1997 14 429 138. 

Bierkens, J., Maes, J. and Plaetse, F.V. (1998) Dose-dependent induction of heat shock protein 70 synthesis in Raphidocelis subcapitata following exposure to different classes of environmental pollutants, Environmental Pollution 101 (1), 91-97. 

Fig. 1. Intracellular events involved in steroid hormone action. A. Model in which the receptor is cytosolic and transfers tothe nucleus after binding with steroid (S). The cytosolic 8S receptor consists of a ligand binding unit ( ) and other units, one of which is a 90 kDa heat shock protein ( ). Activation is shown here as involving dimerisation of the ligand binding unit. This simplification of the true events applies to oestradiol receptor but not necessarily for other receptor classes. There is no agreement as to where activation occurs. B. Model in which unliganded receptor (0) is in the nucleus. A conformational change occurs on binding steroid (S) which may result in increased affinity for specific DNA sequences.

Figure 7.11. The effects of exposure temperature on protein synthetic patterns of isolated gill tissue from specimens of 13°C-acclimated Tegula funebralis. Autoradiographic images illustrate newly synthesized (35S-labeled) proteins of several size classes (molecular mass standards are shown in the left lane). Two specimens from each temperature of incubation are shown. At temperatures above 24°C, synthesis of heat-shock proteins in the molecular mass ranges of 38, 70, 77, and 90 kDa is induced. Hsp synthesis becomes an increasingly large fraction of protein synthesis as exposure temperature increases, and by 38°C, only synthesis of hsp70 is observed. By 39° C, no protein synthesis takes place. (Figure modified after Tomanek and Somero, 1999.)...

Sequence Comparisons Proteins called molecular chaperones (described in Chapter 4) assist in the process of protein folding. One class of chaperone found in organisms from bacteria to mammals is heat shock protein 90 (Hsp90). All Hsp90 chaperones contain a 10 amino acid signature sequence, which allows for ready identification of these proteins in sequence databases. Two representations of this signature sequence are shown below. 

Assay developments for important target classes such as protein kinases and phosphatases, proteases, nuclear receptors, G protein-coupled receptors, ion channels, and heat shock proteins... 

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