Bikinin

Bikinin has been used:

• as a glycogen synthase kinase-3 (GSK3) inhibitor in Arabidopsis Col-0 seedlings to test its effect on gene expression
• as a component of induction medium and as a GSK3 inhibitor to test its effect on mesophyll cells in Arabidopsis leaf discs or cotyledons
• as a brassinosteroid agonist to test its effect on the leaf index of R. trichophyllus terrestrial leaves

Bikinin is a strong activator of brassinosteroid (BR) signaling. It is an Arabidopsis GSK-3 Inhibitor, an Arabidopsis SHAGGY-related Kinase Inhibitor, and a GSK-3-like Kinase BIN2 Inhibitor. Bikinin directly inhibits BIN2 (group II GSK3s) by interfering with ATP binding. Bikinin is specific toward a subset of Arabidopsis GSK3 kinases including BIN2 and ASK α, γ, ε, ι, and θ.

This ATP-competitive Arabidopsis GSK-3 inhibitor, (FW = 273.08 g/mol; CAS 188011-69-0), also named 4-(5-bromopyridin-2-ylamino)-4- oxobutanoic acid, is a strong activator of brassinosteroid (BR) signaling. Bikinin directly binds the GSK3 BIN2 and also inhibits the activity of six other Arabidopsis GSK3s. Genome-wide transcript analyses demonstrate that simultaneous inhibition of seven GSK3s is sufficient to activate BR responses. inhibited the SnRK2.3 kinase activity and its T180 phosphorylation in vivo by blocking BIN2 phosphorylation of SnRK2.3 on Thr-180.