Immune receptors

Leukocyte immunoglobulin-like receptors

• Leukocyte immunoglobulin-like receptor

Leukocyte immunoglobulin-like receptors (LIR) or CD85 have extracellular immunoglobulin domains. LIR modulates a variety of immune cells. LIR interacts with class I MHC molecules^[1]. (PDB entry 1p7q). .

Cytokine receptors

TNF receptor superfamily

• Tumor necrosis factor receptor

The extracellular domain of TNFR contains 2 to 6 cysteine-rich domains (CRD). The . The CRDs are involved in binding of TNF^[2]. . Water molecules are shown as red spheres.

• TRAIL (TNF-related apoptosis-inducing ligand) or TNF ligand superfamily 10

TRAIL-R2 is called DR5. (1d0g).

Colony-stimulating factor receptor

• Colony-stimulating factor receptor

The via the conserved kinase DFG motif (colored in salmon) and its gatekeeper threonine residue (colored in magenta)^[3].

• Colony-stimulating factor and receptor

The structure of the complex between M-CSF and its receptor shows that a . There are ^[4]. .

Type I cytokine receptors

• Erythropoietin receptor

(PDB code 1cn4).

• Prolactin receptor

(PDB code 3mzg). The interaction between PRLR and prolactin is strongly pH-dependent and is critically dependent on ^[5]. Water molecules are shown as red spheres. .

Type II cytokine receptors

Interferon receptors

• Interferon receptor
• Structural linkage between ligand discrimination and receptor activation by type I interferons^[6]

All initiate signaling by binding to the same cell surface receptor composed of two subunits called and . The intracellular domains (ICDs) of IFNAR1 and IFNAR2 are associated with the Janus kinases (Jaks) Tyk2 and Jak1, respectively. Upon ligand binding by the IFNAR chains and formation of the signaling complex, these tyrosine kinases trans-phosphorylate and thereby activate each other. Subsequently, the activated Jaks phosphorylate STAT transcription factors, which translocate into the nucleus and activate the expression of hundreds of IFN-stimulated genes. To gain insight into how type I IFNs engage their receptor chains, how the receptor system is able to recognize the large number of different ligands, and how different IFN ligands can evoke different physiological activities, we determined the crystal structures of unliganded , the binary complex , and the ternary ligand-receptor complexes of and binding both receptor chains. A final theoretical ternary structure including was also created. These structures, in conjunction with biochemical and cellular experiments, reveal that the type I IFN receptor uses a mode of ligand interaction that is unique among cytokine receptors, but conserved between different IFNs. Furthermore, ligand discrimination occurs through distinct energetics of shared receptor contacts, and differential IFN signaling is mediated by specific ligand-receptor interface chemistries that lead to different ternary complex stabilities.

• Multiple sclerosis and Interferon Receptors

Interleukin receptors

• Interleukin receptor

Interleukin-20 receptor:

• Flexible regions govern promiscuous binding of IL-24 to receptors IL-20R1 and IL-22R1

Chemokine receptors, two of which acting as binding proteins for HIV (CXCR4 and CCR5). They are G protein-coupled receptors

T-cell receptors

• T-cell receptor
• SP3.4-TCR-HLA-DQ8-α-1-gliadin complex

See also:

• Transmembrane (cell surface) receptors
• Receptor