COMPLEX BETWEEN THE EXTRACELLULAR DOMAIN OF ERYTHROPOIETIN (EPO) RECEPTOR [EBP] AND AN AGONIST PEPTIDE [EMP1]
[EPOR_HUMAN] Defects in EPOR are the cause of familial erythrocytosis type 1 (ECYT1) [MIM:133100]. ECYT1 is an autosomal dominant disorder characterized by increased serum red blood cell mass, elevated hemoglobin and hematocrit, hypersensitivity of erythroid progenitors to erythropoietin, erythropoietin low serum levels, and no increase in platelets nor leukocytes. It has a relatively benign course and does not progress to leukemia.  
[EPOR_HUMAN] Receptor for erythropoietin. Mediates erythropoietin-induced erythroblast proliferation and differentiation. Upon EPO stimulation, EPOR dimerizes triggering the JAK2/STAT5 signaling cascade. In some cell types, can also activate STAT1 and STAT3. May also activate the LYN tyrosine kinase. Isoform EPOR-T acts as a dominant-negative receptor of EPOR-mediated signaling.
Publication Abstract from PubMed
The functional mimicry of a protein by an unrelated small molecule has been a formidable challenge. Now, however, the biological activity of a 166-residue hematopoietic growth hormone, erythropoietin (EPO), with its class 1 cytokine receptor has been mimicked by a 20-residue cyclic peptide unrelated in sequence to the natural ligand. The crystal structure at 2.8 A resolution of a complex of this agonist peptide with the extracellular domain of EPO receptor reveals that a peptide dimer induces an almost perfect twofold dimerization of the receptor. The dimer assembly differs from that of the human growth hormone (hGH) receptor complex and suggests that more than one mode of dimerization may be able to induce signal transduction and cell proliferation. The EPO receptor binding site, defined by peptide interaction, corresponds to the smaller functional epitope identified for hGH receptor. Similarly, the EPO mimetic peptide ligand can be considered as a minimal hormone, and suggests the design of nonpeptidic small molecule mimetics for EPO and other cytokines may indeed be achievable.
Functional mimicry of a protein hormone by a peptide agonist: the EPO receptor complex at 2.8 A.,Livnah O, Stura EA, Johnson DL, Middleton SA, Mulcahy LS, Wrighton NC, Dower WJ, Jolliffe LK, Wilson IA Science. 1996 Jul 26;273(5274):464-71. PMID:8662530
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.