NGF binding to p75NTR induces recruitment of the atypical PKC interacting protein, p62, necessary for coupling IKKbeta with p75NTR. The kinase activity of IRAK1 is necessary for p62 (sequestosome-1) recruitment. IRAK1 interaction with TRAF6 precedes (1 min) its interaction with p62 (5 min). p62 has two protein interaction domains, named UBA and PB1. The UBA domain binds non-covalently to polyubiquitin chains. The PB1 domain has structural homology with the UbL (ubiquitin like) domain, and is able to interact with the 26S proteasome subunit Rpt1. Other protein interaction domains also exist within p62, suggesting that it may have a role in the formation of multimeric signalling complexes.p62 forms a complex with TRAF6, which involves the two domains PB1 at the p62 C-terminal end, and UBA, at the N-terminus.