@article {309589,
	title = {Two copies of the human apolipoprotein C-I gene are linked closely to the apolipoprotein E gene.},
	journal = {J Biol Chem},
	volume = {263},
	year = {1988},
	month = {1988 May 25},
	pages = {7277-86},
	abstract = {<p>The gene for human apolipoprotein (apo) C-I was selected from human genomic cosmid and lambda libraries. Restriction endonuclease analysis showed that the gene for apoC-I is located 5.5 kilobases downstream of the gene for apoE. A copy of the apoC-I gene, apoC-I{\textquoteright}, is located 7.5 kilobases downstream of the apoC-I gene. Both genes contain four exons and three introns; the apoC-I gene is 4653 base pairs long, the apoC-I{\textquoteright} gene 4387 base pairs. In each gene, the first intron is located 20 nucleotides upstream from the translation start signal; the second intron, within the codon of Gly-7 of the signal peptide region; and the third intron, within the codon for Arg39 of the mature plasma protein coding region. The upstream apoC-I gene encodes the known apoC-I plasma protein and differs from the downstream apoC-I{\textquoteright} gene in about 9\% of the exon nucleotide positions. The most important difference between the exons results in a change in the codon for Gln-2 of the signal peptide region, which introduces a translation stop signal in the downstream gene. Major sequence differences are found in the second and third introns of the apoC-I and apoC-I{\textquoteright} genes, which contain 9 and 7.5 copies, respectively, of Alu family sequences. The apoC-I gene is expressed primarily in the liver, and it is activated when monocytes differentiate into macrophages. In contrast, no mRNA product of the apoC-I{\textquoteright} gene can be detected in any tissue, suggesting that it may be a pseudogene. The similar structures and the proximity of the apoE and apoC-I genes suggest that they are derived from a common ancestor. Furthermore, they may be considered to be constituents of a family of seven apolipoprotein genes (apoE, -C-I, -C-II, -C-III, -A-I, -A-II, and -A-IV) that have a common evolutionary origin.</p>
},
	keywords = {Amino Acid Sequence, Apolipoprotein C-I, Apolipoproteins, Apolipoproteins C, Apolipoproteins E, Base Sequence, Biological Evolution, Cloning, Molecular, DNA Restriction Enzymes, Exons, Genes, Genetic Linkage, Humans, Liver, Macrophages, Male, Molecular Sequence Data, Organ Specificity},
	issn = {0021-9258},
	author = {Lauer, S J and Walker, D and Elshourbagy, N A and Reardon, C A and Levy-Wilson, B and Taylor, J M}
}
