Recent Developments in Bacterial Cold-Shock Response

Sangita Phadtare

doi:10.21775/cimb.006.125

Abstract

In response to temperature downshift, a number of changes occur in cellular physiology such as, (i) decrease in membrane fluidity, (ii) stabilization of secondary structures of nucleic acids leading to reduced efficiency of mRNA translation and transcription, (iii) inefficient folding of some proteins, and (iv) hampered ribosome function. Cold-shock response and adaptation has been quite extensively studied in Escherichia coli and Bacillus subtilis. A number of cold shock proteins are induced to counteract these harmful effects of temperature downshift. General principles of cold-shock response along with recent findings on desaturase system, RNA chaperone and transcription antitermination function of CspA homologues, cold shock induction of chaperones and synthesis of trehalose, CspA homologues from hyperthermophilic bacteria and possible multiple roles of cold shock proteins in other stress responses of bacteria are discussed.

Highlights

Temperature is one of the major stresses that all the living organisms have to face
In case of majority of bacteria such as Escherichia coli, upon temperature downshift, there is a transient arrest of cell growth, during which general protein synthesis is severely inhibited
The effect of cold shock is seen at multiple levels such as; (i) decrease in the membrane fluidity affecting the membraneassociated functions such as active transport and protein secretion, (ii) stabilization of the secondary structures of RNA and DNA, leading to reduced efficiency of mRNA translation and transcription, (iii) slow or inefficient folding of some proteins and (iv) ribosomes need to be cold-adapted to function properly at low temperature

Summary

Introduction

Temperature is one of the major stresses that all the living organisms have to face. Heat-shock response from bacteria to human has been extensively studied, while cold-shock response has caught attention of researchers relatively recently. The effect of cold shock is seen at multiple levels such as; (i) decrease in the membrane fluidity affecting the membraneassociated functions such as active transport and protein secretion, (ii) stabilization of the secondary structures of RNA and DNA, leading to reduced efficiency of mRNA translation and transcription, (iii) slow or inefficient folding of some proteins and (iv) ribosomes need to be cold-adapted to function properly at low temperature. These can be overproduced in large quantities at low temperatures using cold-inducible promoters, for example, the promoter of cspA, encoding the major cold shock protein of E. coli.

Results

Conclusion