Paired Immunoglobin Like Type 2 Receptor Alpha (PILRa)

Sequence analysis predicted that the 303-amino acid PILRA protein does not contain an Ig domain per se, but does contain an Ig-like cysteine-based motif involved in intradomain disulfide bonding. PILRA also has a potential N-glycosylation site; numerous O-glycosylation sites; a transmembrane domain; and 3 potential tyrosine phosphorylation sites, 2 of which are within an immunoreceptor tyrosine-based inhibitory motif (ITIM). When expressed in a kidney cell line, immunoblot and BIAcore analysis showed that the approximately 50-kD PILRA glycoprotein was tyrosine-phosphorylated and coprecipitated with SHP1 through a C-terminal tyrosine. Northern blot analysis revealed strong expression of a 1.4-kb transcript in peripheral blood leukocytes, with lower signals in lung, spleen, and placenta as well as in 2 B-cell lines.