The functional range of heat shock proteins to combat environmental toxicity

Almost all the organisms possess a system to cope with the harsh physiochemical factors of environment. such a system is based on a group of stress genes,which show rapid responses in form of stress proteins,especially heat shock proteins,when cells are confronted with insult. heat shock proteins are now known to express in response to variety of toxic and stress conditions including diseases. as a molecular chaperone,against cytotoxicity,these ensure the functional ability of cells by repairing the denatured proteins,cellular structures like cytoskeleton and centrosomes and processes dealing with protein synthesis are stabilized or repaired during a second stress in stress tolerant cells and organisms. in unstressed cells these play an imperative role in the synthesis and transport of normal proteins. their role in certain diseases reveals their potential application in medical field. certain hsp are helpful in coping carcinogenicity caused environmental pollutants and have been suggested to have anti-apoptotic,anti stress and anti-allergic function. their expression is tissue and species specific with respect to type,intensity and duration of a toxicant. these are developmentally regulated and help in process of differentiation and thus their abnormal regulation impairs the normal development. however,their role as biomarker in risk assessment of environmental pollution warrants further research. due to broad functional range,therefore,present review is embracing the functional aspects of smaller and hsp70 families expressing in animals under toxic conditions.