Poster

         Functional Genetics/Genomics

Evaluating Regulatory Module Function within the Mitochondrial Pyruvate Dehydrogenase Complex

Presenting Author
Caroline Keller
Description
Regulatory networks coordinating changes in metabolism are central to how a plant adapts to biotic and abiotic stress. Critical to these coordinated changes are transcriptional shifts programmed by cis-regulatory elements bound by transcription factors. I am testing the role shared cis-regulatory elements play in controlling the co-regulation of all the genes for a single enzyme complex. These cis-regulatory elements control gene expression when they are bound by transcription factors. Because the cis-regulatory elements are shared across the genes in the complex, their coordinated regulation by a transcription factor creates a regulatory module, but it is unclear if all the genes need to be coordinated for maximal module function. For example, if one gene in the complex loses a cis-regulatory element, it may not alter complex function as residual expression from other modules and protein stoichiometry can be sufficient to compensate.To understand how modular membership shapes enzymatic function, I am using CRISPR/Cas9 to abolish mutual cis-regulatory elements within the promoters of genes required for the Pyruvate Dehydrogenase enzyme complex. This complex is composed of three apoenzymes and is an important intermediary between glycolysis and the TCA cycle. This will be tested by transforming Arabidopsis thaliana with different combinations of these cis-element mutations. Plants will be phenotyped with detached leaf assays, metabolomics, and transcriptomics. This study of modular organization will provide data to predict genotype-to-phenotype relationships for regulatory interactions, biotechnology, and crop improvement in California.