Early events in erythropoietin-induced signaling

The cloning of the erythropoietin receptor (EpoR) in 1989 has allowed very rapid progress in our understanding of the early intracellular events that may be triggered by erythropoietin (Epo) in erythroid progenitor cells. From studies carried out primarily with cell lines expressing exogenous wild-type and mutant EpoRs, it appears that the activated EpoR is capable of triggering many of the same cascades that are utilized by receptors possessing endogenous tyrosine kinase domains. The major challenge over the next decade lies in seeing if these same signaling pathways are also utilized by normal Epo-responsive erythroid progenitors, discriminating between proliferation and differentiation inducing events in these cells, and determining whether various hematologic disorders can be attributed to aberrations in these signaling pathways.