Domain:The box 1 motif is required for JAK interaction and/or activation. ,Domain:The cytoplasmic domain may be essential for intracellular signal transduction by activation of JAK tyrosine kinase and STATs. ,Domain:The WSXWS motif appears to be necessary for proper protein folding and thereby efficient intracellular transport and cell-surface receptor binding. ,Function:Receptor for obesity factor (leptin) . On ligand binding , mediates signaling through JAK2/STAT3. Involved in the regulation of fat metabolism and , in a hematopoietic pathway , required for normal lymphopoiesis. May play a role in reproduction. Can also mediate the ERK/FOS signaling pathway. ,PTM:On ligand binding , phosphorylated on two conserved C-terminal tyrosine residues (isoform B only) by JAK2. Tyr-986 is required for complete binding and activation of PTPN11 , ERK/FOS activation and , for interaction with SOCS3 (By similarity) . Phosphorylation on Tyr-1141 is required for STAT3 binding/activation. ,similarity:Belongs to the type I cytokine receptor family. Type 2 subfamily. ,similarity:Contains 1 Ig-like (immunoglobulin-like) domain. ,similarity:Contains 4 fibronectin type-III domains. ,subunit:On leptin stimulation , homodimerizes. The phosphorylated receptor binds a number of SH2 domain-containing proteins such as STAT3 , PTPN11 , and SOCS3 (By similarity) . Interaction with SOCS3 inhibits LRb signaling. ,tissue specificity:Isoform A is expressed in fetal liver and in hematopoietic tissues and choroid plexus. In adults highest expression in heart , liver , small intestine , prostate and ovary. Low level in lung and kidney. Isoform B is highly expressed in hypothalamus. ,
展开内容