Covering a broad dynamic range: information processing at the erythropoietin receptor.
Cell surface receptors convert extracellular cues into receptor activation, thereby triggering intracellular signaling networks and controlling cellular decisions. A major unresolved issue is the identification of receptor properties that critically determine processing of ligand-encoded information. We show by mathematical modeling of quantitative data and experimental validation that rapid ligand depletion and replenishment of the cell surface receptor are characteristic features of the erythropoietin (Epo) receptor (EpoR). The amount of Epo-EpoR complexes and EpoR activation integrated over time corresponds linearly to ligand input; this process is carried out over a broad range of ligand concentrations. This relation depends solely on EpoR turnover independent of ligand binding, which suggests an essential role of large intracellular receptor pools. These receptor properties enable the system to cope with basal and acute demand in the hematopoietic system.
Becker
Verena
V
Division Systems Biology of Signal Transduction, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany.
Schilling
Marcel
M
Bachmann
Julie
J
Baumann
Ute
U
Raue
Andreas
A
Maiwald
Thomas
T
Timmer
Jens
J
Klingmüller
Ursula
U
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D003198:Computer Simulation; D004705:Endocytosis; D000068817:Epoetin Alfa; D004921:Erythropoietin / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D008024:Ligands; D051379:Mice; D008954:Models, Biological; D011485:Protein Binding; D017467:Receptors, Erythropoietin / Q000378:metabolism*; D011994:Recombinant Proteins; D015398:Signal Transduction
D008024:Ligands; D017467:Receptors, Erythropoietin; D011994:Recombinant Proteins; D004921:Erythropoietin; D000068817:Epoetin Alfa