Description: Human Interleukin-31 (IL-31) is a T-cell derived cytokine. The human IL-31 cDNA encodes a 164 amino acid precursor that contains a 23 amino acid signal peptide and a 141 amino acid mature protein. Human and mouse IL-31 share 24% amino acid sequence identity in the mature region. IL-31 is mainly associated with activated T cells and preferentially expressed by Th2 rather than Th1 cells. IL-31 signals via a heterodimeric receptor complex composed of a 120 kDa, gp130-like molecule termed IL-31RA (also GPL and GLM-R) and a 180 kDa oncostatin M receptor (OSM Rb). GPL/OSMR signaling is a strong activator of STAT3 and STAT5, and can also activate STAT1, Jak1, and Jak2 signaling pathways. IL-31 signaling has been shown to involve the Jak/STAT pathway, the PI3 kinase/AKT cascade, and MAP kinase pathway. The IL-31 receptor is constitutively expressed by keratinocytes and upregulated by IFN-g on monocytes.
