Sakaino Masayoshi, Kataoka Takao, Taketani Shigeru
Department of Biotechnology and Insect Biomedical Center, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
J Biochem. 2009 Jun;145(6):733-8. doi: 10.1093/jb/mvp030. Epub 2009 Feb 27.
Ferrochelatase (FECH) catalyses the insertion of ferrous ions into protoporphyrin IX to produce haem at the haem-biosynthetic pathway. The present study characterized a variant mRNA of mouse FECH, which was generated by skipping exon II (FECH-v). FECH-v mRNA was expressed in various tissues, including the liver and kidney, of mice. The mRNA was also expressed in mouse and human non-erythroid and erythroid cells to a different extent but could not be translated into functional FECH. The ratio of FECH-v/FECH increased in hemin-treated Balb/3T3 cells, while it decreased after treatment with succinylacetone, an inhibitor of haem biosynthesis, strongly suggesting that FECH expression was decreased by increasing the level of intracellular haem. These results demonstrated the haem-dependent negative feedback regulation of the expression of FECH at a post-transcriptional level.
铁螯合酶（FECH）在血红素生物合成途径中催化亚铁离子插入原卟啉IX以生成血红素。本研究鉴定了小鼠FECH的一种可变mRNA，它是通过外显子II跳跃产生的（FECH-v）。FECH-v mRNA在小鼠的各种组织中表达，包括肝脏和肾脏。该mRNA在小鼠和人类的非红细胞和红细胞中也有不同程度的表达，但不能翻译成有功能的FECH。在血红素处理的Balb/3T3细胞中，FECH-v/FECH的比例增加，而在用血红素生物合成抑制剂琥珀酰丙酮处理后该比例降低，这强烈表明细胞内血红素水平升高会降低FECH的表达。这些结果证明了在转录后水平上血红素对FECH表达的负反馈调节。
