leukocyte immunoglobulin-like receptor subfamily B member 4; leukocyte immunoglobulin-like receptor 5; LIR-5; immunoglobulin-like transcript 3; ILT-3; monocyte inhibitory receptor HM18; CD85 antigen-like family member K; CD85k (LILRB4, ILT3, LIR5)

Function

• receptor for class 2 MHC antigens
• recognizes a broad spectrum of HLA-A, HLA-B, HLA-C & HLA-G alleles
• involved in down-regulation of the immune response & development of tolerance towards transplants
• interferes with TNFRSF5-signaling & NF-kappa-B up-regulation
• inhibits receptor-mediated phosphorylation of cellular proteins & mobilization of intracellular Ca+2
• binds PTPN6 when phosphorylated

Structure

• contains 3 ITIM motifs
• phosphorylated ITIM motif can bind the SH2 domain of several SH2 domain-containing phosphatases
• contains 2 Ig-like C2-type domains (immunoglobulin-like)

Compartment

• cell membrane; single-pass type 1 membrane protein
• ligand binding leads to internalization & translocation to an antigen-processing compartment

Alternative splicing

• named isoforms=3
• alternative use of an acceptor site

Expression

• detected in monocytes, macrophages, dendritic cells, lung, natural killer cells & B-cells
• upon contact with CD8(+)CD28(-), alloantigen-specific T suppressor (Ts) cells

More general terms

• CD85 or leukocyte immunoglobulin-like receptor family protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=11006
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:11006
• OMIM: https://mirror.omim.org/entry/604821
• UniProt: http://www.uniprot.org/uniprot/Q8NHJ6.html