Gene Regulation By Cold Shock Proteins via Transcription Antitermination

Multiple changes occur in cellular physiology in response to downshift from optimal temperature. Some of these are harmful and may interfere with further cell growth. Cold shock proteins are induced to counteract these effects. Cold shock proteins of the CspA family are RNA chaperones that resolve secondary structures in the nucleic acids. At low temperatures, secondary structures in nascent transcripts become stabilized, promoting premature transcription termination and excessive pausing. The CspA family proteins function as antiterminating and antipausing transcription factors. CspA and its homologues play critical roles for cell survival and growth at low temperature by allowing transcription of essential promoter-distal genes, whose expression at low temperatures is attenuated by secondary-structure formation in nascent transcripts.