title: Characterization and evolution of the expressed rat ferritin light subunit gene and its pseudogene family. Conservation of sequences within noncoding regions of ferritin genes.
abstract: 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.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004247:DNA / Q000235:genetics; D004274:DNA, Recombinant; D005293:Ferritins / Q000235:genetics*; D006801:Humans; D007438:Introns; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004274:DNA, Recombinant; D004247:DNA; D005293:Ferritins