Active serine carboxypeptidase with broad substrate preference, including basic and hydrophilic groups. Processes a protein involved in an early event in the brassinosteroid signaling pathway. Preferential release of a C-terminal arginine or lysine residue. Completely inhibited by phenylmethylsulfonyl fluoride (PMSF) and partially by leupeptin. Optimum pH is 5.5. Optimum temperature is 50 degrees Celsius. Heterodimer. Expressed in shoots, leaves, cauline leaves, siliques and flowers. Expressed a low levels in roots and stems. N-glycosylated. Was isolated as a suppressor of bri1 mutant phenotype. The serine carboxypeptidase activity is necessary for suppression of bri1 mutant phenotype. Belongs to the peptidase S10 family.