Elevated levels of stress proteins associated with bacterial symbiosis in Amoeba proteus and soybean root nodule cells.
Obligatory bacterial endosymbionts of Amoeba proteus and symbiotic Bradyrhizobium japonicum bacteroids in soybean-root nodules contained large amounts of 67-kDa and 65-kDa proteins, respectively, antigenically related to groEL of E. coli and the 58-kDa heat-shock protein of Tetrahymena. Monoclonal antibodies against the 67-kDa protein recognized groEL analogs from several different organisms. The quantity of the stress protein in symbiotic B. japonicum bacteroids was augmented seven times that in the free-living counterparts. The increase in these proteins in endosymbionts, as determined by immunoblot techniques, indicated that intracellular symbiosis is a stress condition even when the symbiotic relationship is considered to be mutually beneficial. Mitochondria and chloroplasts may also be under a stressed condition like endosymbionts in view of the presence of heat-shock proteins in these cell organelles.
Choi
E Y
EY
Department of Zoology, University of Tennesse, Knoxville 37996-0810.
Ahn
G S
GS
Jeon
K W
KW
D000656:Amoeba / Q000378:metabolism / Q000382:microbiology; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D018833:Chaperonins; D003429:Cross Reactions; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008970:Molecular Weight; D010944:Plants / Q000378:metabolism; D012230:Rhizobiaceae / Q000378:metabolism; D013559:Symbiosis
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D006360:Heat-Shock Proteins; D018833:Chaperonins