Brassinosteroids signal through two receptor-like kinases

Both animals and plants use steroids to regulate their growth and development, but their mechanisms for steroid perception are different. Animal steroids are mainly recognized by intracellular steroid receptors, whereas plant steroids are perceived by cell-surface receptors that contain a transmembrane receptor serine/ threonine kinase. Recent studies suggest that heterodimerization between two receptor kinases might be a key step in steroid perception and signaling in plants.