The Class II cytokine receptor (CRF2) family: overview and patterns of receptor–ligand interactions

• Published in: Cytokine & growth factor reviews Vol. 15; no. 1; pp. 33 - 48
• Main Authors: Langer, Jerome A, Cutrone, E.Cali, Kotenko, Sergei
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2004
• Subjects: Amino Acid Sequence; Animals; Cytokine receptors; Cytokines; Cytokines - biosynthesis; Cytokines - metabolism; Dimerization; DNA Mutational Analysis; Genome; Humans; Interferons; Ligands; Models, Biological; Models, Molecular; Molecular Sequence Data; Multigene Family; Phylogeny; Protein Binding; Protein Structure, Tertiary; Receptors, Cytokine - biosynthesis; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Statistics as Topic; Cytokines; Cytokine receptors; Interferons
• ISSN: 1359-6101
• DOI: 10.1016/j.cytogfr.2003.10.001

Expanded genomic information has driven the discovery of new members of the human Class II family of cytokine receptors (CRF2), which now includes 12 proteins. The corresponding cytokines have been identified, paired with their receptors and initially characterized for function. These cytokines include: a new human Type I IFN, IFN-κ; molecules related to IL-10 (IL-19, IL-20, IL-22, IL-24, IL-26); and IFN-λs (IL-28/29), which have antiviral and cell stimulatory activities reminiscent of Type I IFNs, but act through a distinct receptor. In response to ligand binding, the CRF2 proteins form heterodimers, leading to cytokine-specific cellular responses; these diverse physiological functions are just beginning to be explored. Progress in structural and mutational analysis of ligand–receptor interactions now presents a more reliable framework for understanding receptor–ligand interactions, and for predicting key regions in less well studied members of the CRF2 family. The relationships between the CRF2 proteins will be summarized, as will the progress in identifying patterns of receptor interactions with ligands.