Apoptosis-associated speck-like protein containing a CARD (ASC) (ASC)

Apoptosis-associated speck-like protein containing a CARD (ASC), encoded by the PYCARD gene, is a critical adapter protein that mediates the assembly of various inflammasome complexes in the innate immune system [1.2.1, 1.2.2]. It consists of two protein-protein interaction domains: an N-terminal pyrin domain (PYD) and a C-terminal caspase recruitment domain (CARD) [1.2.4]. Upon sensing danger signals via receptors like NLRP3 or AIM2, ASC undergoes rapid oligomerization into large supramolecular aggregates known as "ASC specks" [1.3.3]. These specks act as a platform for the recruitment and activation of pro-caspase-1, which subsequently processes pro-inflammatory cytokines IL-1β and IL-18 into their active forms and triggers pyroptotic cell death [1.1.1, 1.4.1]. ASC is a central node in the inflammatory response and is implicated in a wide range of pathologies, including neurodegenerative diseases (Parkinson's and Alzheimer's), autoimmune disorders (Multiple Sclerosis and Psoriasis), and metabolic conditions (Gout and Type 2 Diabetes) [1.1.2, 1.3.1, 1.3.3]. In drug development, ASC is targeted to inhibit the formation of the inflammasome complex or to prevent the propagation of extracellular ASC specks that can amplify inflammation [1.1.3, 1.4.1]. Therapeutic strategies include monoclonal antibodies like IC100 and small molecule inhibitors that disrupt ASC oligomerization [1.1.2, 1.4.1]. However, because ASC is shared by multiple inflammasomes, therapeutic modulation carries risks of broad immunosuppression and potential effects on programmed cell death pathways [1.4.1].

Other names

PYCARDCARD5TMS1TMSPYD and CARD domain containing proteinTarget of methylation-induced silencing 1

Inhibition of ASC oligomerization or disruption of protein-protein interactions (PYD-PYD or CARD-CARD) within the inflammasome complex to prevent caspase-1 activation and cytokine release [1.1.3, 1.4.1].