Two coding regions closely linked to the rat apolipoprotein E gene: nucleotide sequences of rat apolipoprotein C-I and ECL cDNA.
Restriction fragments isolated from a 17-kb rat genomic DNA clone containing the gene for apolipoprotein (apo) E were radiolabeled and used to screen a rat liver cDNA library. A cDNA clone hybridizing to a 6-kb genomic DNA fragment was isolated and the nucleotide sequence of the cDNA insert determined. The sequence was homologous to the sequence for human apo C-I and was used to derive the corresponding amino acid sequence. Unlike human apo C-I, mature rat apo C-I contains histidine, lacks valine, and has alanine at the C terminus and aspartate as the N terminus. Screening the rat liver cDNA library with a radiolabeled 1.9-kb restriction fragment from the genomic DNA clone containing the rat apo E gene identified another cDNA clone (ECL cDNA). Nucleotide sequencing yielded a derived 75-amino-acid sequence for the ECL protein with a hydrophobicity profile similar to that of rat apo C-I. Northern analysis demonstrated a 0.50-kb band for ECL mRNA. The tissue-specific expression of the gene is similar to that of rat apo C-I. This study indicates that the rat apo C-I and ECL genes are closely linked, about 4.5 and 12 kb downstream of the apo E gene, respectively.
Shen
P
P
Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia.
Howlett
G J
GJ
D000595:Amino Acid Sequence; D000818:Animals; D053302:Apolipoprotein C-I; D001056:Apolipoproteins C / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004285:Dogs; D015723:Gene Library; D008040:Genetic Linkage; D006801:Humans; D008099:Liver / Q000502:physiology*; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011487:Protein Conformation; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D053302:Apolipoprotein C-I; D001056:Apolipoproteins C; D001057:Apolipoproteins E; D012333:RNA, Messenger; D012313:RNA; D004247:DNA