Pro-opiomelanocortin (POMC) is synthesised by corticotrophs of the anterior pituitary. Within these cells, prohormone convertase 1 cleaves POMC primarily into which products?
- A ACTH, beta-lipotropin, and beta-endorphin ✓
- B Alpha-MSH and CLIP only
- C ACTH and gamma-MSH only
- D Beta-endorphin and enkephalin
Correct answer: A. ACTH, beta-lipotropin, and beta-endorphin
Explanation
In anterior pituitary corticotrophs, PC1 (prohormone convertase 1) cleaves POMC into ACTH, beta-lipotropin, and beta-endorphin; further processing stops there because corticotrophs lack PC2. In hypothalamic neurons expressing PC2, ACTH is further split to alpha-MSH and CLIP. Intermediate lobe cells in lower species produce MSH-rich products. Enkephalins derive from proenkephalin, a separate precursor entirely, making option D incorrect.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.