PILRA

Paired immunoglobin like type 2 receptor alpha is a protein that in humans is encoded by the PILRA gene. ^[5]

PILRA
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3WUZ, 3WV0, 4NFB
Identifiers
Aliases	PILRA, FDF03, paired immunoglobin like type 2 receptor alpha
External IDs	OMIM: 605341; MGI: 2450529; HomoloGene: 8387; GeneCards: PILRA; OMA:PILRA - orthologs
Gene location (Human) Chr. Chromosome 7 (human)[1] Band 7q22.1 Start 100,367,530 bp[1] End 100,400,096 bp[1]
Gene location (Mouse) Chr. Chromosome 5 (mouse)[2] Band 5|5 G2 Start 137,820,214 bp[2] End 137,834,543 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in monocyte granulocyte blood cerebellar hemisphere right hemisphere of cerebellum spleen bone marrow right lung bone marrow cell appendix Top expressed in granulocyte blood spleen urethra bone marrow tibiofemoral joint right lung lobe liver embryo jejunum More reference expression data BioGPS n/a
Gene ontology Molecular function MHC class I protein binding protein binding Cellular component integral component of membrane extracellular region extracellular exosome membrane plasma membrane Biological process viral process signal transduction transmembrane receptor protein tyrosine kinase signaling pathway regulation of immune response Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 29992 231805 Ensembl ENSG00000085514 ENSMUSG00000046245 UniProt Q9UKJ1 Q2YFS3 RefSeq (mRNA) NM_178273 NM_013439 NM_178272 NM_153510 RefSeq (protein) NP_038467 NP_840056 NP_840057 NP_705730 Location (UCSC) Chr 7: 100.37 – 100.4 Mb Chr 5: 137.82 – 137.83 Mb PubMed search [3] [4]
Wikidata
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Function

Cell signaling pathways rely on a dynamic interaction between activating and inhibiting processes. SHP-1-mediated dephosphorylation of protein tyrosine residues is central to the regulation of several cell signaling pathways. Two types of inhibitory receptor superfamily members are immunoreceptor tyrosine-based inhibitory motif (ITIM)-bearing receptors and their non-ITIM-bearing, activating counterparts.

Control of cell signaling via SHP-1 is thought to occur through a balance between PILRalpha-mediated inhibition and PILRbeta-mediated activation. These paired immunoglobulin-like receptor genes are located in a tandem head-to-tail orientation on chromosome 7. This particular gene encodes the ITIM-bearing member of the receptor pair, which functions in the inhibitory role. Alternative splicing has been observed at this locus, and three variants, each encoding a distinct isoform, are described.

In contrast to PILRbeta, which has only one known natural ligand, PILRalpha has many known protein-protein interactions.^[6] PILRalpha recruits PTPN6 and PTPN1 via interactions of its ITIM motifs.^[7] PILRalpha is also used by some viruses, notably HSV-1, for cell entry.^[6][8]

Structure

As with other paired receptors, PILRalpha has a longer cytoplasmic tail compared to PILRbeta and features two intracellular ITIM motifs.^[7][9] PILRalpha has an extracellular domain with a siglec-like immunoglobulin fold that substitutes hydrophobic interactions for the siglec fold's characteristic disulfide bond. The structure of this domain is very similar to that of PILRbeta, but the two proteins nevertheless have different binding affinities for sialic acid.^[6]