The interaction between TASL and SLC15A4 links endolysosomal Toll-like receptors to the transcription factor IRF5, providing a mechanistic explanation for the involvement of the complex in systemic lupus erythematosus.
Toll-like receptors (TLRs) have a crucial role in the recognition of pathogens and initiation of immune responses(1-3). Here we show that a previously uncharacterized protein encoded by CXorf21-a gene that is associated with systemic lupus erythematosus(4,5)-interacts with the endolysosomal transporter SLC15A4, an essential but poorly understood component of the endolysosomal TLR machinery also linked to autoimmune disease(4,6-9). Loss of this type-I-interferon-inducible protein, which we refer to as '