Receptor for TNFSF5/CD40LG (By similarity). Transduces TRAF6- and MAP3K8-mediated signals that activate ERK in macrophages and B cells, leading to induction of immunoglobulin secretion (PubMed:12881420). Monomer and homodimer. Interacts with TRAF1, TRAF2 and TRAF6 (By similarity). Interacts with TRAF3 and TRAF5. Interacts with TRAF6 and MAP3K8; the interaction is required for ERK activation.