Disease relevance of groEL

• Using a photocross-linking approach, we have identified the 20S heat-shock GroEL protein as the major cytosolic component which forms a complex with the unfolded newly synthesized pre-beta-lactamase or chloramphenicol acetyltransferase in Escherichia coli [1].
• The GroEL protein from E. coli, but not from Mycobacterium tuberculosis and Mycobacterium leprae, also showed activity in the bone resorption assay [2].
• Spontaneous mutants (ogr) of phiX174, S13, and the G phages can grow on groL- strains [3].
• Isolation and characterization of a Treponema pallidum major 60-kilodalton protein resembling the groEL protein of Escherichia coli [4].
• Members of the genus Buchnera are intracellular symbionts harbored by the aphid bacteriocyte which selectively synthesize symbionin, a homolog of the Escherichia coli GroEL protein, in vivo [5].

High impact information on groEL

• Nucleotide sequence analysis revealed that yeast hsp60 is related to the groEL protein of E. coli and the RUBISCO-binding protein (RBP) of chloroplasts [6].
• The deduced amino acid sequence of P1 shows strong homology (40 to 50% identical residues and an additional 20% conservative replacements) to the 65-kilodalton major antigen of mycobacteria, to the GroEL protein of Escherichia coli, and to the ribulose 1,5-bisphosphate carboxylase-oxygenase (rubisco) subunit binding protein of plant chloroplasts [7].
• This finding is particularly interesting because a chloroplast protein involved in the assembly of ribulose-1,5-bisphosphate carboxylase/oxygenase also is homologous to the groEL protein [8].
• Immunization with several peptides induced a cross-reactive T cell proliferative response to the homologous GroEL protein isolated from E. coli [9].
• The N-terminal amino acid sequence of the protein is identical to that of GroEL protein [10].

Chemical compound and disease context of groEL

• The small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase and its precursor expressed in Escherichia coli are associated with groEL protein [8].
• The 58 kDa GroEL protein was expressed in Escherichia coli in fusion with glutathione S:-transferase and the fusion protein was purified from IPTG-induced bacterial lysates by affinity chromatography on glutathione-Sepharose [11].

Biological context of groEL

• These findings suggest a possible role of the GroEL protein in cell division [10].
• To identify those residues of the GroEL protein that interact with GroES, we have exploited the thermosensitive phenotype of strains bearing mutations at one or the other of two GroEL-interacting residues of GroES [12].
• We conclude that the oligomer of TpN60 is homologous to the groEL protein and related chaperonins found in a wide variety of procaryotes and eucaryotes and thus may represent a heat shock protein involved in protein folding and assembly [4].
• The bicistronic 2.4-kilobase transcript from this operon, barely detectable in RNA preparations from cells grown at 30 degrees C, accumulated approximately 120-fold in preparations from cells grown for 20 min at 45 degrees C. Under these conditions, GroEL protein accumulated to 10-fold-higher levels [13].
• Changes of only three different amino acid substitutions in GroEL protein were found among these six groEL suppressor mutations [12].

Associations of groEL with chemical compounds

• Like the groEL protein, symbionin was able to reconstitute dimeric ribulose 1,5-bisphosphate carboxylase/oxygenase holoenzyme from its unfolded subunits in vitro, suggesting that this protein functions as a molecular chaperon in the endosymbiont [14].

Physical interactions of groEL

• Recently, we have identified a region of the GroES protein that interacts with the GroEL protein [12].

Analytical, diagnostic and therapeutic context of groEL

• Electron microscopy of the isolated complex revealed a ringlike structure with a diameter of approximately 16 nm which was very similar in appearance to the groEL protein [4].
• The results obtained show that antibodies to the mycobacterial hsp65 cross-reacted with the E. coli GroEL protein, both in ELISA and Western blot experiments, but not with the human hsp60 [15].

References