Noncoding 3' sequences of the transferrin receptor gene are required for mRNA regulation by iron.
AUTOR(ES)
Owen, D
RESUMO
The cell-surface receptor for transferrin mediates cellular uptake of iron from serum. Transferrin receptor protein and mRNA levels are increased in cells treated with iron chelating agents, and are decreased by treatment with iron salts or hemin. Here we report that expression of human transferrin receptor cDNA constructions in stably transfected mouse fibroblasts is regulated both by the iron chelator, desferrioxamine, and by hemin. We found that sequences within the 3' noncoding region are required for the iron-dependent feed-back regulation of receptor expression, whereas the presence of the transferrin receptor promoter region is not necessary. Regulation by iron is observed when transcription is initiated at either the SV-40 early promoter or the transferrin receptor promoter, but deletion of a 2.3 kb fragment within the 2.6 kb 3' noncoding region of the cDNA abolishes regulation and increases the constitutive level of receptor expression. Furthermore, the 3' deletion does not affect the decrease in receptors which is observed in response to growth arrest, indicating that transferrin receptor expression is controlled by at least two distinct mechanisms.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=553931Documentos Relacionados
- Iron regulation of transferrin receptor mRNA levels requires iron-responsive elements and a rapid turnover determinant in the 3' untranslated region of the mRNA.
- Coding and noncoding sequences at the 3' end of yeast histone H2B mRNA confer cell cycle regulation.
- Chicken transferrin receptor gene: conservation 3' noncoding sequences and expression in erythroid cells.
- Do eukaryotic mRNA 5' noncoding sequences base-pair with the 18 S ribosomal RNA 3' terminus?
- The histone mRNA 3' end is required for localization of histone mRNA to polyribosomes.