Practice question

CLAVATA1 encodes leucine-rich repeat receptor-like kinase with extracellular leucine-rich repeat recognition domain, transmembrane helix, and intracellular serine/threonine kinase effector domain expressed in organizing center and L3 layers. Its specific high-affinity ligand is mature processed CLV3 CLE peptide secreted from overlying central zone stem cells after proteolytic cleavage and arabinosylation. Binding of CLV3 to CLV1 often in complex with CLV2 and pseudokinase CORYNE triggers autophosphorylation, MAPK cascade, and transcriptional repression of WUS. Spatial separation between peptide source and receptor field generates paracrine negative feedback loop controlling maintenance.