Activation of the plant mevalonate pathway by extracellular ATP

Abstract

The mevalonate (MVA) pathway plays a critical role in multiple cellular processes in both animals and plants. In plants, the products of this pathway impact growth and development, as well as the response to environmental stress. A forward genetic screen of Arabidopsis thaliana using Ca2+ imaging identified mevalonate kinase (MVK) as a critical component of plant purinergic signaling. MVK interacts directly with the plant extracellular ATP (eATP) receptor P2K1 and is phosphorylated by P2K1 in response to eATP. Mutation of P2K1-mediated phosphorylation sites in MVK eliminates the ATP-induced cytoplasmic calcium response, MVK enzymatic activity, and suppresses pathogen defense. The data demonstrate that the plasma membrane associated P2K1 directly impacts plant cellular metabolism by phosphorylation of MVK, a key enzyme in the mevalonate pathway. The results underline the importance of purinergic signaling in plants and the ability of eATP to influence the activity of a key metabolite pathway with global effects on plant metabolism.

ATP drives efficient terpene biosynthesis in marine thraustochytrids

“…For every three acetyl-CoA that enter the mevalonate pathway, cells need to invest 3 ATP and 2 NADPH, which could explain why increased ATP production favors squalene synthesis in Thraustochytrium sp.. In plants, extracellular ATP can also contribute to the activation of the MVA pathway by phosphorylating mevalonate kinase through an ATP receptor P2K1 (39). However, it is not known whether the same mechanism exists in thraustochytrids.…”