Structure and properties of small heat shock proteins (sHsp) and their interaction with cytoskeleton proteins

The modern classification of small heat shock proteins (sHsp) is presented and peculiarities of their primary structure and the mechanism of formation of oligomeric complexes are described. Data on phosphorylation of sHsp by different protein kinases are presented and the effect of phosphorylation on oligomeric state and chaperone activity of sHsp is discussed. Intracellular location of sHsp under normal and stress conditions is described and it is emphasized that under certain condition sHsp interact with different elements of cytoskeleton. The literature concerning the effect of sHsp on polymerization of actin in vitro is analyzed. An attempt is made to compare effects of sHsp on polymerization of actin in vitro with the results obtained on living cells under normal conditions and after heat shock or hormone action. The literature concerning possible effects of sHsp on cell motility is also analyzed.     

Thermotolerance in Fungi: The Role of Heat Shock Proteins and Trehalose

The parallel synthesis of heat shock proteins and trehalose in response to heat shock did not allow the role of these compounds in the acquisition of thermotolerance by fungal cells to be established for a long time. This review analyses experimental data obtained with the use of mutant fungal strains and shows differences in the thermoprotective functions of trehalose and heat shock proteins in relation to cell membranes and macromolecules. The main emphasis has been placed on data demonstrating the thermoprotective role of trehalose in fungi, the present-day understanding of its biological functions, and mechanisms of trehalose interaction with subcellular structures and cell macromolecules.__________Translated from Mikrobiologiya, Vol. 74, No. 3, 2005, pp. 293–304. p ]Original Russian Text Copyright © 2005 by Tereshina.     

昆虫的热休克反应和热休克蛋白

热休克（热激heatshock）是指短暂、迅速地向高温转换所诱导出的一种固定的应激反应。诱导该反应的温度在种与种之间有所不同。热休克反应最明显的特征是：伴随着正常蛋白质合成的抑制,一部分特殊蛋白质的诱导和表达增加,即为热休克蛋白（heatshockproteins,HSPs）。尽管热休克蛋白的合成也能被其它形式的应激反应所诱导,将它们认为是应激蛋白可能更恰当,但人们习惯上仍将这类蛋白质称为热休克蛋白。由于热休克反应和热休克蛋白是在果蝇（Drosophiliamelanogaster）中最初发现的,故在昆虫中,特别是果蝇等双翅目昆虫中研究得较深入…     

Heat Shock Proteins: Functions and Role in Adaptation to Hyperthermia

The results are generalized of many-year studies into the adaptive role of heat shock proteins in different animals, including the representatives of cold- and warm-blooded species that inhabit regions with different thermal conditions. Adaptive evolution of the response to hyperthermia can lead to different results depending on the species. The thermal threshold of induction of the heat shock proteins in desert thermophylic species is, as a rule, higher than in the moderate climate species. In addition, thermoresistant species are often characterized by a certain level of heat shock proteins in cells even at a physiologically normal temperature. Although adaptation to hyperthermia is achieved in most cases without changes in the number of heat shock genes, they can be amplified in some cases in termophylic species. The role of mobile elements in evolution of the heat shock genes was shown and approach was developed for directional introduction of mutations in the promoter regions of these genes.__________Translated from Ontogenez, Vol. 36, No. 4, 2005, pp. 265–273.Original Russian Text Copyright © 2005 by Evgen’ev, Garbuz, Zatsepina.     

Fas ligation and tumor necrosis factor α activation of murine astrocytes promote heat shock factor-1 activation and heat shock protein expression leading to chemokine induction and cell survival

Death-inducing ligands tumor necrosis factor alpha (TNFα) and Fas ligand (FasL) do not kill cultured astrocytes; instead they induce a variety of chemokines including macrophage-inflammatory protein-1α/CC chemokine ligand 3 (CCL3), monocyte chemoattractant protein-1 (CC CCL-2), macrophage-inflammatory protein-2/CXC chemokine ligand 2 (CXCL2, a murine homologue of interleukin 8), and interferon-induced protein of 10 kDa (CXCL10). Induction is enhanced by protein synthesis inhibition suggesting the existence of endogenous inhibitors. ERK, NF-κB, heat shock factor-1 (HSF-1) and heat shock proteins were examined for their possible roles in signal transduction. Inhibition of ERK activation by PD98059 partially inhibited expression of all but FasL-induced CXCL10. Although inhibition of NF-κB DNA binding inhibited chemokine induction, PD98059 did not inhibit TNFα-induced NF-κB DNA binding suggesting that ERK serves an NF-κB-independent pathway. Heat shock itself induced astrocytic chemokine expression; both TNFα and FasL induced HSF-1 DNA binding and Hsp72 production; and Hsp72-induced chemokine expression. Inhibition of either HSF-1 binding with quercetin or heat shock protein synthesis with KNK437 compromised chemokine induction without compromising cell survival. These data suggest that the induction of heat shock proteins via HSF-1 contribute to the TNFα- and FasL-induced expression of chemokines in astrocytes.