ISCU

• OMIM: 611911
• UniProt: Q9H1K1

The iron-sulfur cluster protein scaffold ( ICSU ) is a protein in chordates, which is part of a protein complex that accomplishes the production of iron-sulfur clusters. These clusters are cofactors for several essential enzymes. In addition, ICSU serves as an independent transport protein for the cluster. There are two isoforms of the protein which is localized in the cytosol and the mitochondrion. In human ISCU is produced mainly in the heart, liver, skeletal muscle, brain, pancreas, kidney, lung and placenta. Mutations at the ISCU gene can, for lack of the protein, and this lead to the ( rare ) lack of the appropriate enzymes with myopathy.

Function

Assembling the iron -sulfur cluster

ISCU is part of the complex, producing Fe-S cluster. ISCU thereby takes over the role of the binding of the iron atoms, which are transported from ISCA zoom, while the enzyme cysteine ​​desulfurase provide under Cysteinverbrauch sulfur atoms. First of [2Fe -2S ] is assembled, the dimerization finally [ 4Fe -4S]. This process can take place both in the mitochondria and in the cytosol, after which the finished [ 4Fe -4S] is transported to the plasma.

Cluster transport

After the cluster synthesis transported him ISCU from the mitochondrion. The corresponding membrane transporter is the ABC7 - iron transporter ( TCDB ​​: 3.A.1.210.4 ). They shall be the act is the only process that transports large amounts of iron from the mitochondria, since accumulates both in ISCU deficiency, as well as ABCB7 iron deficiency in these organelles, ultimately leading to their failure.