ISSN:
1572-8773
Keywords:
aconitase
;
ferritin
;
iron-responsive element binding protein
;
iron-responsive elements
;
iron-sulfur clusters
;
RNA binding
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract 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 respresses 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01061319
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