Enables K63-linked polyubiquitin modification-dependent protein binding activity and identical protein binding activity. Involved in several processes, including anoikis; negative regulation of endoplasmic reticulum stress-induced intrinsic apoptotic signaling pathway; and positive regulation of macroautophagy. Acts upstream of or within B cell homeostasis and activation of NF-kappaB-inducing kinase activity. Located in cytoplasm. Is expressed in early conceptus; genitourinary system; and musculature. Used to study Bloch-Sulzberger syndrome and fatty liver disease. Human ortholog(s) of this gene implicated in Behcet's disease; Bloch-Sulzberger syndrome; immunodeficiency 33; and learning disability. Orthologous to human IKBKG (inhibitor of nuclear factor kappa B kinase regulatory subunit gamma). [provided by Alliance of Genome Resources, Apr 2022]