A molecular aspect of symbiotic interactions between the weevil Sitophilus oryzae and its endosymbiotic bacteria: over-expression of a chaperonin

Biochem Biophys Res Commun. 1997 Oct 29;239(3):769-74. doi: 10.1006/bbrc.1997.7552.


Specific proteins of symbiosis were analyzed by the comparison of two-dimensional electrophoresis protein patterns of symbiotic and aposymbiotic strains of the weevil Sitophilus oryzae. One protein was shown to be exclusively expressed in the aposymbiotic strain and three proteins, including a chaperonin, were characterized in the symbiotic strain pattern. The groE-like operon, encoding the two chaperonins groES and GroEL-like proteins of the endocytobiotes, was sequenced. It was found to be very similar to the groE operon of Escherichia coli (82% identity). In vitro and ex vivo experiments of protein labelling demonstrated that almost 40% of the endocytobiote protein synthesis ex vivo is focused on the GroEL-like protein. Finally, we showed by northern blotting that heat shock at 38 degrees C results in groEL mRNA accumulation inside the endocytobiotes. This work supports the hypothesis that chaperonins could have an essential physiological function in the maintenance of the symbiotic association.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chaperonin 10 / chemistry
  • Chaperonin 10 / genetics
  • Chaperonin 10 / metabolism
  • Chaperonin 60 / biosynthesis*
  • Chaperonin 60 / chemistry
  • Chaperonin 60 / genetics
  • Coleoptera / genetics
  • Coleoptera / microbiology*
  • Cytosol / chemistry
  • Cytosol / microbiology
  • Electrophoresis, Gel, Two-Dimensional
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / physiology*
  • Gene Expression Regulation, Bacterial
  • Molecular Sequence Data
  • Symbiosis* / genetics


  • Chaperonin 10
  • Chaperonin 60

Associated data

  • GENBANK/AF005236