Details

Autor(en) / Beteiligte

• Rouault, T A
• Haile, D J
• Downey, W E
• Philpott, C C
• Tang, C
• Samaniego, F
• Chin, J
• Paul, I
• Orloff, D
• Harford, J B

Titel

An iron-sulfur cluster plays a novel regulatory role in the iron-responsive element binding protein

Ist Teil von

• Biometals, 1992, Vol.5 (3), p.131-140

Ort / Verlag

Netherlands

Erscheinungsjahr

1992

Quelle

SpringerLink

Beschreibungen/Notizen

• Post-transcriptional regulation of genes important in iron metabolism, ferritin and the transferrin receptor (TfR), is achieved through regulated binding of a cytosolic protein, the iron-responsive element binding protein (IRE-BP), to RNA stem-loop motifs known as iron-responsive elements (IREs). Binding of the IRE-BP represses ferritin translation and represses degradation of the TfR mRNA. The IRE-BP senses iron levels and accordingly modifies binding to IREs through a novel sensing mechanism. An iron-sulfur cluster of the IRE-BP reversibly binds iron; when cytosolic iron levels are depleted, the cluster becomes depleted of iron and the IRE-BP acquires the capacity to bind IREs. When cytosolic iron levels are replete, the IRE-BP loses RNA binding capacity, but acquires enzymatic activity as a functional aconitase. RNA binding and aconitase activity are mutually exclusive activities of the IRE-BP, and the state of the iron-sulfur cluster determines how the IRE-BP will function.