A molecular aspect of symbiotic interactions between the weevil Sitophilus oryzae and its endosymbiotic bacteria: over-expression of a chaperonin.
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.
Charles
H
H
Laboratoire de Biologie Appliquée, INSA 406, UA-INRA 203, SDI-CNRS 5128, Villeurbanne, France.
Heddi
A
A
Guillaud
J
J
Nardon
C
C
Nardon
P
P
D000595:Amino Acid Sequence; D000818:Animals; D018835:Chaperonin 10 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018834:Chaperonin 60 / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D001517:Coleoptera / Q000235:genetics / Q000382:microbiology*; D003600:Cytosol / Q000737:chemistry / Q000382:microbiology; D015180:Electrophoresis, Gel, Two-Dimensional; D004755:Enterobacteriaceae / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D013559:Symbiosis / Q000235:genetics
D018835:Chaperonin 10; D018834:Chaperonin 60