Mullner, E. W.Neupert, B.Kühn, L. C.2008-02-252008-02-252008-02-25198910.1016/0092-8674(89)90851-9https://infoscience.epfl.ch/handle/20.500.14299/19036Iron regulates human transferrin receptor (hTR) expression by modulating the stability of cytoplasmic hTR mRNA. This regulation requires a distinct secondary structure in the mRNA 3' untranslated region. We identified a specific cytoplasmic factor that binds simultaneously to four homologous palindromes within the regulatory domain. Iron chelator induced the RNA binding activity 25-fold in parallel with mRNA. Upon the addition of iron salts, a rapid decay of factor activity closely preceded hTR mRNA degradation, indicating a causal relation. Induction and decay occurred posttranscriptionally. Binding of the factor to hTR mRNA palindromes was competed by 5' regulatory sequences of ferritin mRNA, which are responsible for iron-dependent translational control. These results suggest that cellular iron maintains its homeostasis by coordinate regulation of hTR and ferritin expression via a common factor.text::journal::journal article::research article