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Volume 60, Issue 1, Pages 106-111 (January 2003)


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Do mitochondria regulate cellular iron homeostasis through citric acid and haem production? Implications for cancer and other diseases

S JohnsonCorresponding Author Informationemail address

Received 25 January 2001; accepted 28 May 2002.

Abstract 

Citric acid is produced industrially by depriving Aspergillus niger of iron. The lack of Fe deactivates mitochondrial aconitase and interrupts the krebs cycle, causing the mitochondria to release citric acid as a siderophore (an Fe getter). When the mitochondrion has plenty of Fe and the cell has enough ATP, aerobic phosphorylation stops and fatty acid or haem synthesis take place, when the cell has plenty of haem, haem synthesis stops. Since most of the Fe activity in the cell is related to the mitochondria, I hypothesise that in the animal cell when the mitochondria are low in Fe, citric acid acts as a signal that triggers the production of transferrin receptor messenger RNA (TrR mRNA) in the nucleus, which in the absence of Fe causes the expression of transferrin receptor. When the cell has plenty of Fe, cytosolic aconitase detaches itself from the transferrin receptor and ferritin mRNA stopping expression of the former and initiating expression of the latter. The detached cytosolic aconitase transforms the citric acid, blocking the production of the transferrin receptor mRNA.

Moses Lake, WA, USA

Corresponding Author InformationCorrespondence to: S. Johnson, Independent Researcher, 3743 Thayer Rd., Moses Lake, WA 98837, USA. Phone: +1-509-765-6815; Fax: +1-509-765-6815

PII: S0306-9877(02)00342-0


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