The function of PELI3 (pellino E3 ubiquitin protein ligase family member 3, ENSG00000174516) is as follows. E3 ubiquitin ligase catalyzing the covalent attachment of ubiquitin moieties onto substrate proteins (PubMed:12874243, PubMed:17675297). Involved in the TLR and IL-1 signaling pathways via interaction with the complex containing IRAK kinases and TRAF6 (PubMed:12874243). Mediates 'Lys-63'-linked polyubiquitination of IRAK1 (PubMed:12874243). Can activate AP1/JUN and ELK1 (PubMed:12874243). Acts as a regulator of innate immunity by mediating 'Lys-63'-linked polyubiquitination of RIPK2 downstream of NOD1 and NOD2, thereby transforming RIPK2 into a scaffolding protein for downstream effectors, ultimately leading to activation of the NF-kappa-B and MAP kinases signaling (By similarity). Catalyzes 'Lys-63'-linked polyubiquitination of RIPK2 in parallel of XIAP (By similarity). {ECO:0000250|UniProtKB:Q8BXR6, ECO:0000269|PubMed:12874243, ECO:0000269|PubMed:17675297}.