Pyroptosis is a form of programmed cell death distinct from apoptosis. The key executioner protein that forms membrane pores in pyroptosis is:

• A Caspase-3 activated by cytochrome c release
• B Gasdermin D (GSDMD), cleaved by caspase-1 or caspase-11 ✓
• C MLKL (mixed lineage kinase domain-like), phosphorylated by RIPK3
• D Perforin secreted by cytotoxic T lymphocytes

Explanation

Pyroptosis is an inflammatory form of programmed cell death triggered by inflammasome activation. Caspase-1 (or caspase-4/5/11 in the non-canonical pathway) cleaves gasdermin D; the N-terminal fragment of GSDMD oligomerizes and inserts into the plasma membrane, forming large pores that cause osmotic lysis and release of pro-inflammatory cytokines (IL-1beta, IL-18). This is distinct from apoptosis (caspase-3/7, membrane blebbing, no inflammation) and necroptosis (RIPK3 phosphorylates MLKL, which forms pores — same pore mechanism but different triggers and signaling).

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.