11/07/2016 - RGD publishes a new diagram page for the iron homeostasis pathway and an updated heme biosynthetic pathway diagram page

Iron (Fe) is essential for a wide range of important and vital processes as a component of heme- and iron-sulfur cluster (ISC)-containing proteins and as a cofactor for non-heme iron-dependent enzymes. Various aspects of iron homeostasis, such as uptake, efflux and storage, post-transcriptional regulation and intracellular trafficking are described and captured in the diagram on the left. The essential pathways of iron utilization – heme biosynthesis and Fe-S cluster biogenesis and assembly, are only briefly presented in this diagram as these pathways have their own dedicated diagram pages - an updated heme biosynthesis pathway is presented on the right.

Iron homeostasis pathway

Heme biosynthetic pathway - updated

Very few life forms can survive in the absence of iron. Iron can be in its reduced, ferrous Fe(II)/Fe2+ form or in the oxidized, ferric Fe(III)/Fe3+ form. The redox cycling of iron underlies the chemistry of its biological functions. It also makes it potentially toxic, as it can lead to the production of reactive oxygen species (ROS). Iron deficiency or iron overload contributes to the development of numerous conditions and the proper maintenance of iron homeostasis is crucial for the well-being of cells, tissues and organs. Click here to explore this important and complex system. Heme serves as a prosthetic group for enzymes and proteins involved in a broad range of important cellular processes such as oxygen transport and storage, photosynthesis, redox, signaling and drug metabolism. The biosynthesis of heme is a conserved pathway that consists of single pyrrole synthesis, assembly of pyrroles into the tetrapyrrole ring, side chain modification and iron insertion into the ring. Click here to explore this important pathway of iron utilization.