Leibold E A, Munro H N
J Biol Chem. 1987 May 25;262(15):7335-41.
The iron storage protein ferritin consists of two types of subunits of different molecular weight, heavy (H) and light (L). The rat genome contains approximately 20 copies of the ferritin L-subunit gene, of which we have sequenced seven. One is an expressed ferritin gene containing three introns located between the alpha-helical domains of the L-subunit protein. The remaining six have the characteristics of processed pseudogenes. Sequence divergence suggest that these pseudogenes arose approximately 3-12 X 10(6) years ago, well within the 30 X 10(6) years of divergence of rat and mouse. By using intron probes derived from the expressed ferritin L-gene, a homologous second copy has been identified in some Fischer rats. Comparison of the 5'-untranslated region of the rat L-gene with the published sequences of this region of the human L (Santoro, C., Marone, M., Ferrone, M., Costanzo, F., Colombo, M., Minganti, C., Cortese, R., and Silengo, L. (1986) Nucleic Acids Res. 14, 2863-2876) and H (Costanzo, F., Colombo, M., Staempfli, S., Santoro, C., Marone, M., Frank, R., Delius, H., and Cortese, R. (1986) Nucleic Acids Res. 14, 721-735) genes and of a bullfrog cDNA (Didsbury, J. R., Theil, E. C., Kaufman, R. E., and Dickey, L. F. (1986) J. Biol. Chem. 261, 949-955) show a strongly conserved 28-base pair sequence, suggesting a translational regulatory function. The 5' flanking region of the rat L-gene contains sequences homologous to those in the flanking areas of the human L- and H-genes. The implications of these conserved sequences for control of ferritin expression are discussed.
铁储存蛋白铁蛋白由两种分子量不同的亚基组成，即重链（H）和轻链（L）。大鼠基因组包含约20个铁蛋白L亚基基因拷贝，我们已对其中7个进行了测序。其中一个是表达的铁蛋白基因，含有位于L亚基蛋白α螺旋结构域之间的三个内含子。其余六个具有加工假基因的特征。序列差异表明这些假基因大约在3 - 12×10⁶年前出现，这完全在大鼠和小鼠30×10⁶年的分化时间范围内。通过使用从表达的铁蛋白L基因衍生的内含子探针，在一些费希尔大鼠中鉴定出了一个同源的第二个拷贝。将大鼠L基因的5'非翻译区与已发表的人类L（桑托罗，C.，马罗内，M.，费罗内，M.，科斯坦佐，F.，科隆博，M.，明甘蒂，C.，科尔泰斯，R.，和西伦戈，L.（1986）核酸研究。14，2863 - 2876）和H（科斯坦佐，F.，科隆博，M.，施泰姆普利，S.，桑托罗，C.，马罗内，M.，弗兰克，R.，德利乌斯，H.，和科尔泰斯，R.（1986）核酸研究。14，721 - 735）基因以及牛蛙cDNA（迪兹伯里，J.R.，泰尔，E.C.，考夫曼，R.E.，和迪基，L.F.（1986）生物化学杂志。261，949 - 955）的该区域序列进行比较，发现有一个高度保守的28碱基对序列，提示其具有翻译调控功能。大鼠L基因的5'侧翼区包含与人L基因和H基因侧翼区域同源的序列。讨论了这些保守序列对铁蛋白表达调控的意义。
