Protein Modification and Turnover
Kriezel, Heather K. , Kauk, Jennifer M. , Ngo, Stephani K. , Brusslan, Judy .
Determination of the Oligomeric State and Native Size of the Arabidopsis Proteases cGEP and cAAP.
Proteolytic enzymes play numerous key roles in the development and metabolism of all organisms. Our research has centered on two Arabidopsis thaliana serine proteases cGEP (At2g47309) and cAAP (At5g36210). cGEP may play a role in plant senescence, and both cGEP and cAAP function to enhance survival under carbon-starved etiolated conditions. These proteases are orthologous to mammalian, plant, algal, and cyanobacterial proteases that have been found to form dimers and higher order protein complexes. The structure of AAP from an archaeon has been solved, and the dimerization domain has been identified. Toward determining the oligomeric state of these proteases, a yeast two-hybrid system was used to detect if heterodimers or homodimers form with cGEP and cAAP. The results of these experiments showed no interactions. To further investigate protein-protein interactions his-tagged cGEP and cAAP lines were generated. There was no success in the formation of a his-tagged cGEP line, but the his-tagged cAAP line was subject to native page and immunoblot analysis and found to be monomeric. Experiments that are underway include site-directed mutagenesis of amino acids in cAAP that are found in the same location as the archaeon dimerization domain. These mutated sequences are being introduced into caap mutants and cAAP activity assays will be done to determine the effect of dimerization domain mutations on cAAP activity. Also in progress is the generation of N-terminal myc-tagged cGEP lines for native electrophoresis and pull-down assays for identification of potential binding partners.
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1 - California State University Long Beach, Department of Biological Sciences, 1250 Bellflower Blvd., Long Beach,, CA, 90840-3702, USA
2 - California State University Long Beach, Department of Biological Sciences
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM