Dissertation
FUNCTIONAL IMPACTS OF ARABIDOPSIS THALIANA MATH-BTB/POZ PROTEINS ON THE ERF/AP2 TRANSCRIPTION FACTOR FAMILY
Doctor of Philosophy (PhD), Washington State University
01/2014
Handle:
https://hdl.handle.net/2376/111791
Abstract
The Ubiquitin (Ub)/ 26S proteasome pathway is utilized in plants to finely tune the levels of available protein in the cell, and thereby controlling cellular responses. CULLIN-based E3 ligases (further referred to as CRL3) play decisive roles in this pathway by selecting specific substrate proteins for ubiquitylation and subsequent degradation. They accomplish this by associating with substrate adaptor proteins that contain a BRIC-A-BRAC, TRAM-TRACK AND BROAD COMPLEX/POX VIRUS AND ZINC FINGER (BTB/POZ) domain. Arabidopsis thaliana encodes for a small family of six BTB/POZ proteins that have a secondary MEPRIN AND TUMOR NECROSIS FACTOR RECEPTOR ASSOCIATED FACTOR HOMOLOGY (MATH) domain, and which is needed for recognition and binding of substrates. The family is further referred to as BPM proteins for MATH-BTB/POZ.
This work demonstrates that CRL3BPM E3 ligases assemble in planta with members of the ETHYLENE RESPONSE FACTOR/APETALA2 (ERF/AP2) transcription factor family. The interaction of CRL3BPM E3 ligases with their substrates results in the degradation of these substrates through the 26S proteasome. For the ERF/AP2 transcription factor RAP2.4 novel target genes were identified and we can show that the CRL3BPM-RAP2.4 interplay is critical for their expression. chromatin immunoprecipitation (ChIP) assays further showed that the E3 ligase interacts with RAP2.4 at the chromatin level.
ERF/AP2 proteins are often critical regulators of plant development, abiotic stress tolerance, and metabolism. The generation and analysis of mutant plants affected in the expression of all BPM members, showed that the corresponding plants are also widely affected in these processes, further supporting a functional connection between CRL3BPM and ERF/AP2 activities.
Taken together, these results provide novel information about CRL3BPM E3 ligases activity in higher plants, and emphasize their importance for plant development, abiotic stress tolerance, and metabolism.
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Details
- Title
- FUNCTIONAL IMPACTS OF ARABIDOPSIS THALIANA MATH-BTB/POZ PROTEINS ON THE ERF/AP2 TRANSCRIPTION FACTOR FAMILY
- Creators
- Joo Hyun Lee
- Contributors
- Hanjo Hellmann (Advisor)John Browse (Committee Member)Michael Knoblauch (Committee Member)Andrew McCubbin (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Program in Molecular Plant Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 143
- Identifiers
- 99900581533901842
- Language
- English
- Resource Type
- Dissertation