Functions as sorting adapter in different signaling pathways to facilitate downstream signaling leading to type I interferon induction. In TLR4 signaling, physically bridges TLR4 and TICAM1 and functionally transmits signal to TICAM1 in early endosomes after endocytosis of TLR4. In TLR2 signaling, physically bridges TLR2 and MYD88 and is required for the TLR2-dependent movement of MYD88 to endosomes following ligand engagement. Involved in IL-18 signaling and is proposed to function as a sorting adapter for MYD88 in IL-18 signaling during adaptive immune response. Forms a complex with RAB11FIP2 that is recruited to the phagosomes to promote the activation of the actin-regulatory GTPases RAC1 and CDC42 and subsequent phagocytosis of Gram-negative bacteria. Homodimer. Interacts with TLR4, TICAM1, IRF3 and IRF7 in response to LPS. Interacts with IL1R1, IL1RAP, IRAK2, IRAK3 and TRAF6. Interacts with protein kinase-inactive mutants of IRAK1 and IRAK4. Isoform 1 interacts with isoform 2; the interaction occurs in late endosomes and disrupts the interaction between isoform 1 and TICAM1. Interacts with MYD88; the interaction decreases after IL-18 stimulation in a time-dependent manner. Interacts with IL18R1 and IL18RAP. Interacts with TLR2. Interacts with RAB11FIP2. Localized to the plasma membrane as a result of myristoylation. The TIR domain mediates the interaction with TRAF6 and MYD88. Myristoylated. Required for membrane association which is critical for its ability to initiate efficient signaling. Phosphorylated by PRKCE in response to LPS. Phosphorylation is essential for its function. It is depleted from the membrane upon phosphorylation. Tyrosine phosphorylation is inhibited by phosphatase PTPN4.