Function of mevalonate kinase proteoforms in the adaptation to specific climates
The cytosolic mevalonate (MEV) pathway is one of the two metabolic routes to supply isoprenoid precursors in plants. It provides isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) for the synthesis of brassinosteroid phytohormones, phytosterols, ubiquinones, dolichols as well as specialized metabolites (sesqui- and triterpenoids), and for the farnesylation of proteins. Despite its importance, relatively little is known about its regulation in plants. We identified a number of non-synonymous SNPs in the Arabidopsis gene coding for mevalonate kinase (AtMVK) within the 1001 Arabidopsis sequenced accessions. One of them showed strong association with several climate parameters at a position which is conserved in humans and whose mutation leads to disease. In this project we will 1) perform extensive enzymatic characterization of the different proteoforms of AtMVK and model their impact on enzyme structure and activity, 2) determine the structure of the AtMVK proteoforms and of the AtMVK protein complex using cryo-EM and 3) evaluate the impact of the AtMVK proteoforms on plant fitness under various abiotic stressors using advanced molecular genetics and phenotyping.