LIFESCI 3N03 Midterm: 3N03 M3 Iron
Document Summary
Regulation of iron - mechanisms hormonal-dependent homeostatic main mechanism systemic regulation via hepcidin. Hepcidin = main player at individual cellular level hormonal-independent homeostatic mechanisms cells" iron content = cellular regulation via ire-bp/irp. Hepcidin and regulation of systemic iron hormone secreted primarily by hepatocytes into bloodstream. 2. 7-kda (25 amino acid) with 4 disulphide bonds. N-term essential for iron-regulatory function interacts with ferroportin is a receptor for hepcidin - binds to its n-terminal region. Hep-fpn interaction inhibits iron efflux from enterocytes, macrophages, and hepatocytes. Fpn is expressed in duodenal enterocytes, re macrophages, hepatocytes, erythroid precursor cells. Main players when it comes to sensing plasma levels or iron: Hfe - interacts with both receptors and acts as a sensor. Bmp6 - the liver releases it as an extracellular signal and acts on the hepatocyte itself to increase hepcidin levels. Tmprss6 - has inhibitory effect on the signalling pathway for hepcidin synthesis oomf. Note: transferrin and hfe cannot be bound at the same time.