Piecing together details of valine catabolism in Arabidopsis thaliana

Monday, July 28, 2025 4:10 PM to 4:30 PM · 20 min. (America/Chicago)

203AB

Biochemistry

Information

Abstract Description: Valine degradation is characterized by seven enzyme-catalyzed reactions ending with the production of propionyl-CoA. In plants, this pathway primarily occurs in the mitochondria, although there is some evidence for parts of the pathway occurring in other areas of the cell. The first four reactions of the pathway are fairly well characterized as they are shared with the catabolic pathways for the other branched-chain amino acids leucine and isoleucine. These three amino acids are critical for plant growth and development during periods of extended darkness, germination, and senescence by serving as alternative energy sources. The objective of this work was to increase our understanding of the final three reactions of the pathway - those that are catalyzed by the enzymes 3-hydroxyisobutyryl-CoA hydrolase (CHY4), 3-hydroxyisobutyrate dehydrogenase (HDH1), and methylmalonate semialdehyde dehydrogenase (MMSD). Using reverse genetics, metabolite profiling, and structure/function studies, we have identified several characteristics of these three enzymes and their reactions that reveal their importance for plant growth and development and the production of beta-alanine, a key molecule for the synthesis of coenzyme A and vitamin B5.

Equity and Inclusion:

Mode

Plant Biology 2025: Milwaukee

Day

7/28/2025

Event Type

Concurrent

Session Overview

Biochemistry 2: Metabolism + Regulation