Selectin Ligand Interactor Cytoplasmic 1 (SLIC1)

SNX20 interacts with the cytoplasmic domain of PSGL1 (SELPLG) and cycles PSGL1 into endosomes.The protein contains a proline-rich N terminus with 3 potential SH3 domain-interacting PxxP motifs, followed by a central phox homology (PX) domain and a 128-amino acid C terminus. It shares 77% identity with the mouse protein. Northern blot analysis detected a 3-kb transcript in various hematopoietic tissues, as well as liver, small intestine, placenta, and lung. SLIC1 had an apparent molecular mass of 43 kD, slightly higher than the calculated molecular mass of 36 kD, by SDS-PAGE. Confocal microscopy demonstrated that SLIC1 localized to endosomes in transfected COS cells.SLIC1 interacted with the cytoplasmic domain of PSGL1. The PX domain of SLIC1 bound phosphoinositides and targeted the SLIC1/PSGL1 complex to endosomes.