Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 6, 1997
Publication Date: N/A
Technical Abstract: It is becoming increasingly clear that molecular chaperone proteins do not act individually, but rather in multi-component complexes designated 'machines'. By itself, the recombinant Arabidopsis Stress70 protein, AtK1, has low in vitro levels of ATPase and chaperone activities. Addition of an equimolar amount of recombinant AtJ2 increases both ATPase and chaperone activities of AtK1 by 3 to 10-fold. Addition of recombinant AtE1, a nucleotide-exchange factor, has no effect upon the activities of AtK1 alone, but further increases both ATPase and chaperone activities of AtK1 plus AtJ2 by 1 to 1.5-fold. There is a direct physical interaction between AtK1 and AtE1, while AtJ2 appears to interact with the AtK1-AtE1-target protein ternary complex. Experiments are in progress to identify additional members of the cytoplasmic chaperone machine.