title: GroEL to DnaK chaperone network behind the stability modulation of σ(32) at physiological temperature in Escherichia coli.
abstract: The stability of heat-shock transcription factor σ(32) in Escherichia coli has long been known to be modulated only by its own transcribed chaperone DnaK. Very few reports suggest a role for another heat-shock chaperone, GroEL, for maintenance of cellular σ(32) level. The present study demonstrates in vivo physical association between GroEL and σ(32) in E. coli at physiological temperature. This study further reveals that neither DnaK nor GroEL singly can modulate σ(32) stability in vivo; there is an ordered network between them, where GroEL acts upstream of DnaK.
authors.affiliation: Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India.
authors.forename: Monobesh
authors.initials: M
authors.lastname: Patra
authors.affiliation: Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India.
authors.forename: Sourav Singha
authors.initials: SS
authors.lastname: Roy
authors.affiliation: Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India.
authors.forename: Rakhi
authors.initials: R
authors.lastname: Dasgupta
authors.affiliation: Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India. Electronic address: tarakdb@yahoo.com.
authors.forename: Tarakdas
authors.initials: T
authors.lastname: Basu
mesh_terms: D018834:Chaperonin 60 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D047468:Immunoprecipitation; D007700:Kinetics; D050296:Microbial Viability; D008954:Models, Biological; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D017510:Protein Folding; D055550:Protein Stability; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012808:Sigma Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
chemical_list: D018834:Chaperonin 60; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D050505:Mutant Proteins; D011994:Recombinant Proteins; D012808:Sigma Factor; C069774:heat-shock sigma factor 32; C063842:dnaK protein, E coli
keywords: Chaperone network; DnaK; E. coli; GroEL; Physiological temperature; Stability of σ(32)