Submitted to: Protein Expression and Purification
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2000
Publication Date: 7/1/2000
Citation: ZHOU, R., KROCZYNSKA, B., MIERNYK, J.A. EXPRESSION OF THE ARABIDOPSIS THALIANA ATJ2 CO-CHAPERONE PROTEIN IN PICHIA PASTORIS. PROTEIN EXPRESSION AND PURIFICATION. 2000. V. 19(2). P. 253-258. Interpretive Summary: The ability of a plant to respond to environmental stress is a major factor in agricultural productivity. When subjected to an abrupt elevation in temperature, plants respond by switching off normal housekeeping activities and switching on production of the elements of the stress response. Genetic material that contains information necessary for production of one important stress response element was isolated from the model plant thale cress, and studied. A method was developed to produce large amounts of the plant stress protein for biochemical analysis. Chemical properties of the protein were defined. This information will be important to researchers in their attempts to increase agricultural productivity by altering the ability of plants to respond to environmental stress, and to other plant scientists who will try to design more efficient crop plants through either classical breeding or biotechnology.
Technical Abstract: A vector was constructed for intracellular expression of the Arabidopsis thaliana DnaJ homologue AtJ2 in the methylotrophic yeast Pichia pastoris. The vector includes DNA encoding an amino-terminal histidine-tag, in order to simplify protein purification. Shake-flask cultures could be induced to produce approximately 250 mg per L of AtJ2. Purified recombinant AtJ2 was able to stimulate the ATPase activities of both the Escherichia coli and Zea mays cytoplasmic Stress70 chaperone proteins five- to nine-fold. The carboxy terminus of AtJ2 is -CAQQ, a protein farnesylation motif. When transformed P. pastoris was induced to synthesize AtJ2 in the presence of tritiated mevalonolactone, radioactivity was incorporated into the protein suggesting farnesylation.