Submitted to: Cell Stress and Chaperones
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 31, 2001
Publication Date: July 1, 2001
Citation: MIERNYK, J.A. THE J-DOMAIN PROTEINS OF ARABIDOPSIS THALIANA: AN UNEXPECTEDLY LARGE AND DIVERSE FAMILY OF CHAPERONES. CELL STRESS AND CHAPERONES. 2001. V. 6(3). P. 209-218. Interpretive Summary: The ability of a plant to both survive and respond to environmental stress is a major factor in agricultural productivity, because plants can neither move nor adjust their internal temperature. Instead, when subjected to abrupt changes in temperature, plants respond by switching off normal housekeeping activities and switching on elements of the stress response network. The complete sequence of the genome of the model plant Thale Cress was recently released by The Genome Initiative. This is the first complete genome sequence for any plant. Exhaustive analysis of this sequence resulted in identification of 89 genes, all of the members of one class of stress proteins. This class of proteins is considerably larger in plants than in other organisms. A model based upon analysis of this gene family can be used as the basis for understanding the stress response in more complex and agriculturally important plants. This information will be eimportant to researchers in their attempts to alter 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 total of 89 J-domain proteins were identified in the genome of the model flowering plant Thale Cress (Arabidopsis thaliana). The deduced amino acid sequences of the J-domain proteins were analyzed for an assortment of structural features and motifs. Based upon the results of sequence comparisons and structure/function predictions, 51 distinct families were identified. The families ranged in size from one to six members. Subcellular localizations of the A. thaliana J-domain proteins were predicted; species were found in both the soluble and membrane compartments of all cellular organelles. Based upon digital Northern analysis, the J- domain proteins could be separated into groups of low, medium and moderate expression levels. This genomics-based analysis of the A. thaliana J- domain proteins establishes a framework for detailed studies of biological function and specificity. It additionally provides a comprehensive basis for evolutionary comparisons.