排序方式: 共有127条查询结果,搜索用时 31 毫秒
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Wingert RA Galloway JL Barut B Foott H Fraenkel P Axe JL Weber GJ Dooley K Davidson AJ Schmid B Schmidt B Paw BH Shaw GC Kingsley P Palis J Schubert H Chen O Kaplan J Zon LI;Tübingen Screen Consortium 《Nature》2005,436(7053):1035-1039
Iron is required to produce haem and iron-sulphur (Fe-S) clusters, processes thought to occur independently. Here we show that the hypochromic anaemia in shiraz (sir) zebrafish mutants is caused by deficiency of glutaredoxin 5 (grx5), a gene required in yeast for Fe-S cluster assembly. We found that grx5 was expressed in erythroid cells of zebrafish and mice. Zebrafish grx5 rescued the assembly of grx5 yeast Fe-S, showing that the biochemical function of grx5 is evolutionarily conserved. In contrast to yeast, vertebrates use iron regulatory protein 1 (IRP1) to sense intracellular iron and regulate mRNA stability or the translation of iron metabolism genes. We found that loss of Fe-S cluster assembly in sir animals activated IRP1 and blocked haem biosynthesis catalysed by aminolaevulinate synthase 2 (ALAS2). Overexpression of ALAS2 RNA without the 5' iron response element that binds IRP1 rescued sir embryos, whereas overexpression of ALAS2 including the iron response element did not. Further, antisense knockdown of IRP1 restored sir embryo haemoglobin synthesis. These findings uncover a connection between haem biosynthesis and Fe-S clusters, indicating that haemoglobin production in the differentiating red cell is regulated through Fe-S cluster assembly. 相似文献
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Sam Kaitaniemi Heli Elovaara Kirsi Grön Heidi Kidron Janne Liukkonen Tiina Salminen Marko Salmi Sirpa Jalkanen Kati Elima 《Cellular and molecular life sciences : CMLS》2009,66(16):2743-2757
Semicarbazide-sensitive amine oxidases (SSAOs) catalyze oxidative deamination of primary amines, but the true physiological
function of these enzymes is still poorly understood. Here, we have studied the functional and structural characteristics
of a human cell-surface SSAO, AOC2, which is homologous to the better characterized family member, AOC3. The preferred in
vitro substrates of AOC2 were found to be 2-phenylethylamine, tryptamine and p-tyramine instead of methylamine and benzylamine, the favored substrates of AOC3. Molecular modeling suggested structural
differences between AOC2 and AOC3, which provide AOC2 with the capability to use the larger monoamines as substrates. Even
though AOC2 mRNA was expressed in many tissues, the only tissues with detectable AOC2-like enzyme activity were found in the
eye. Characterization of AOC2 will help in evaluating the contribution of this enzyme to the pathological processes attributed
to the SSAO activity and in designing specific inhibitors for the individual members of the SSAO family.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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