Enables protein kinase binding activity. Involved in several processes, including regulation of defense response to virus; regulation of gene expression; and tumor necrosis factor-mediated signaling pathway. Located in cytoplasmic side of plasma membrane. Part of CD40 receptor complex. Is expressed in several structures, including genitourinary system; hemolymphoid system gland; lower jaw epithelium; lung; and mandibular process. Human ortholog(s) of this gene implicated in brain disease. Orthologous to human TRAF3 (TNF receptor associated factor 3). [provided by Alliance of Genome Resources, Apr 2022]