RIPK2 Protein, Human (P. pastoris, His)

RIPK2, a serine/threonine/tyrosine-protein kinase, plays a pivotal role in orchestrating innate and adaptive immune responses. As a key effector in NOD1 and NOD2 signaling pathways, RIPK2 forms filaments upon activation by bacterial peptidoglycans, recruited via CARD-CARD domains. Autophosphorylation and polyubiquitination follow, involving 'Lys-63'-linked ubiquitin chains by XIAP, BIRC2, and BIRC3, as well as 'Met-1'-linked polyubiquitination by the LUBAC complex. This transforms RIPK2 into a scaffolding protein, recruiting downstream effectors. 'Lys-63'-linked polyubiquitin chains on RIPK2 facilitate the recruitment of IKBKG/NEMO, initiating the activation of IKBKB/IKKB and subsequent NF-kappa-B release from inhibitors. While the kinase activity is dispensable for NOD1 and NOD2 pathways, RIPK2 contributes to tyrosine phosphorylation of ARHGEF2, activating NF-kappa-B through NOD2. Additionally, in adaptive immunity, RIPK2 promotes BCL10 phosphorylation during T-cell receptor engagement, and participates in RHOA inactivation in response to NGFR signaling. This multifaceted kinase stands as a crucial mediator in diverse immune processes.