scholarly journals The activity of sigma 32 is reduced under conditions of excess heat shock protein production in Escherichia coli.

1989 ◽  
Vol 3 (12a) ◽  
pp. 2003-2010 ◽  
Author(s):  
D B Straus ◽  
W A Walter ◽  
C A Gross
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Protein Production ◽  
Excess Heat ◽  
Sigma 32

scholarly journals Visualization and functional analysis of the oligomeric states of Escherichia coli heat shock protein 70 (Hsp70/DnaK)

2011 ◽  
Vol 17 (3) ◽  
pp. 313-327 ◽  
Author(s):  
Andrea D. Thompson ◽  
Steffen M. Bernard ◽  
Georgios Skiniotis ◽  
Jason E. Gestwicki
Keyword(s):  
Escherichia Coli ◽  
Functional Analysis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70

Purification of complexes of nuclear oncogene p53 with rat and Escherichia coli heat shock proteins: in vitro dissociation of hsc70 and dnaK from murine p53 by ATP

1988 ◽  
Vol 8 (3) ◽  
pp. 1206-1215
Author(s):  
C F Clarke ◽  
K Cheng ◽  
A B Frey ◽  
R Stein ◽  
P W Hinds ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Protein Interactions ◽  
Protein Complexes ◽  
P53 Protein ◽  
Immunoaffinity Column ◽  
E Coli ◽  
Shock Proteins

Oligomeric protein complexes containing the nuclear oncogene p53 and the simian virus 40 large tumor antigen (D. I. H. Linzer and A. J. Levine, Cell 17:43-51, 1979), the adenovirus E1B 55-kilodalton (kDa) tumor antigen, and the heat shock protein hsc70 (P. Hinds, C. Finlay, A. Frey, and A. J. Levine, Mol. Cell. Biol. 7:2863-2869, 1987) have all been previously described. To begin isolating, purifying, and testing these complexes for functional activities, we have developed a rapid immunoaffinity column purification. p53-protein complexes are eluted from the immunoaffinity column by using a molar excess of a peptide comprising the epitope recognized by the p53 monoclonal antibody. This mild and specific elution condition allows p53-protein interactions to be maintained. The hsc70-p53 complex from rat cells is heterogeneous in size, with some forms of this complex associated with a 110-kDa protein. The maximum apparent molecular mass of such complexes is 660,000 daltons. Incubation with micromolar levels of ATP dissociates this complex in vitro into p53 and hsc70 110-kDa components. Nonhydrolyzable substrates of ATP fail to promote this dissociation of the complex. Murine p53 synthesized in Escherichia coli has been purified 660-fold on the same antibody affinity column and was found to be associated with an E. coli protein of 70 kDa. Immunoblot analysis with specific antisera demonstrated that this E. coli protein was the heat shock protein dnaK, which has extensive sequence homology with the rat hsc70 protein. Incubation of the immunopurified p53-dnaK complex with ATP resulted in the dissociation of the p53-dnaK complex as it did with the p53-hsc70 complex. This remarkable conservation of p53-heat shock protein interactions and the specificity of dissociation reactions suggest a functionally important role for heat shock proteins in their interactions with oncogene proteins.

scholarly journals Isolation and characterization of Escherichia coli mutants that lack the heat shock sigma factor sigma 32.

1988 ◽  
Vol 170 (8) ◽  
pp. 3640-3649 ◽  
Author(s):  
Y N Zhou ◽  
N Kusukawa ◽  
J W Erickson ◽  
C A Gross ◽  
T Yura
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Sigma Factor ◽  
Isolation And Characterization ◽  
Sigma 32

Protective role of Mycobacterium leprae small heat-shock protein in heterologous hosts, Escherichia coli and Mycobacterium smegmatis, grown under stress

2013 ◽  
Vol 62 (7) ◽  
pp. 959-967 ◽  
Author(s):  
Jayapal Jeya Maheshwari ◽  
Kuppamuthu Dharmalingam
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mycobacterium Smegmatis ◽  
Small Heat Shock Protein ◽  
Mycobacterium Leprae ◽  
Protective Role ◽  
Low Oxygen

The aim of this study is to examine the in vivo role of a small heat-shock protein (sHsp18) from Mycobacterium leprae in the survival of heterologous recombinant hosts carrying the gene encoding this protein under different environmental conditions that are normally encountered by M. leprae during its infection of the human host. Using an Escherichia coli system where shsp18 expression is controlled by its native promoter, we show that expression of shsp18 is induced under low oxygen tension, nutrient depletion and oxidative stress, all of which reflect the natural internal environment of the granulomas where the pathogen resides for long periods. We demonstrate the in vivo chaperone activity of sHsp18 through its ability to confer survival advantage to recombinant E. coli at heat-shock temperatures. Additional evidence for the protective role of sHsp18 was obtained when Mycobacterium smegmatis harbouring a copy of shsp18 was found to multiply better in human macrophages. Furthermore, the autokinase activity of sHsp18 protein demonstrated for what is believed to be the first time in this study implies that some of the functions of sHsp18 might be controlled by the phosphorylation state of this protein. Results from this study suggest that shsp18 might be one of the factors that facilitate the survival and persistence of M. leprae under stress and autophosphorylation of sHsp18 protein could be a mechanism used by this protein to sense changes in the external environment.

Sign in / Sign up

Export Citation Format

Share Document