Structure and function of the iron-responsive element from human ferritin L chain mRNA.
We report the cloning and functional characterization of the iron responsive element (IRE) of human ferritin light (L) chain mRNA from a cDNA library of primary human T lymphocytes. Comparison of this palindromic cDNA element to the IRE predicted from the reported genomic sequence revealed significant differences, resulting in a stem-loop structure with lower stability than the IRE of the heavy (H) chain mRNA. Nevertheless, the L subunit IRE mediated efficient binding of the iron regulatory protein (IRP) in a manner comparable to that of human ferritin H chain mRNA in vitro. In accordance with previous observations on H form transcripts, the cis-acting regulatory IRE motif of human ferritin L chain mRNA was capable of repressing translation under iron deprivation but permitted mobilization of the transcripts into polysomes following iron repletion in vivo.
Mikulits
W
W
Institute of Molecular Biology, Vienna Biocenter, University of Vienna, Austria.
Sauer
T
T
Infante
A A
AA
Garcia-Sanz
J A
JA
Müllner
E W
EW
D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D015342:DNA Probes; D018076:DNA, Complementary / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005293:Ferritins / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D007501:Iron / Q000378:metabolism*; D035925:Iron-Regulatory Proteins; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000737:chemistry* / Q000378:metabolism
D015342:DNA Probes; D018076:DNA, Complementary; D035925:Iron-Regulatory Proteins; D007506:Iron-Sulfur Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D005293:Ferritins; D007501:Iron