NLRP5, short for NOD-like receptor family pyrin domain containing 5, is an intracellular protein that plays a role in early embryogenesis. NLRP5 is also known as NACHT, LRR and PYD domains-containing protein 5 (NALP5), Mater protein homolog (MATER), PYPAF8, PAN11, and CLR19.8, and is one of 14 pyrin domain containing members of the NOD-like receptor family of cytoplasmic receptors known to mammals. Conserved oocyte-specific expression of NLRP5 is consistent among many mammalian species. As a member of the subcortical maternal complex (SCMC), it plays an essential role for zygotes to progress beyond the first embryonic cell divisions. NLRP5 also localizes to the nuclear envelope and mitochondria in germinal vesicle oocytes, suggesting a possible role in mitochondrial function.