Enhanced degradation of the ferritin repressor protein during induction of ferritin messenger RNA translation.
Induction of ferritin synthesis in cultured cells by heme or iron is accompanied by degradation of the ferritin repressor protein (FRP). Intermediates in the degradative pathway apparently include FRP covalently linked in larger aggregates. The effect of iron on FRP degradation is enhanced by porphyrin precursors but is decreased by inhibitors of porphyrin synthesis, which implies that heme is an active agent. These results suggest that translational induction in this system may be caused by enhanced repressor degradation. While unique among translational regulatory systems, this process is common to a variety of other biosynthetic control mechanisms.
Goessling
L S
LS
Department of Biology, Washington University, St. Louis, MO 63130.
Daniels-McQueen
S
S
Bhattacharyya-Pakrasi
M
M
Lin
J J
JJ
Thach
R E
RE
D000624:5-Aminolevulinate Synthetase / Q000235:genetics; D000622:Aminolevulinic Acid / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D005293:Ferritins / Q000096:biosynthesis / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism; D007501:Iron / Q000494:pharmacology; D035941:Iron Regulatory Protein 1; D035925:Iron-Regulatory Proteins; D051379:Mice; D027383:Papillomaviridae; D011162:Porphobilinogen / Q000494:pharmacology; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D011817:Rabbits
D035925:Iron-Regulatory Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011162:Porphobilinogen; D000622:Aminolevulinic Acid; D005293:Ferritins; D007501:Iron; D000624:5-Aminolevulinate Synthetase; D035941:Iron Regulatory Protein 1