Identification and DNA sequence of a human apolipoprotein E cDNA clone.
cDNA clones encoding human apolipoprotein E were identified by screening an adult human liver cDNA library with an oligonucleotide probe. The probe was a mixture of synthetic 14-base long DNA oligomers constructed to correspond to all possible codons for apo-E amino acids 218-222. Plasmids from four of the 20 clones selected by this screening procedure were digested with PstI and all had five internal PstI sites with a total length of the cDNA insert of approximately 900 base pairs. DNA sequence analysis of one of these clones, designated pE-301, revealed that it corresponded to apo-E amino acids 81-299, and contained a standard termination codon, polyadenylation signal, and poly A tail. The DNA sequence examined included the known apo-E polymorphic sites at amino acids 112, 145, and 158, and the mutant apo-E phenotypes can all be explained on the basis of a single base substitution in the first position of each of these codons. This work supports the hypothesis that the apo-E polymorphism is due to mutations in the region of DNA coding for the apo-E structural gene.
D000328:Adult; D000595:Amino Acid Sequence; D001053:Apolipoproteins / Q000235:genetics*; D001057:Apolipoproteins E; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA; D006801:Humans; D008079:Lipoproteins, VLDL / Q000235:genetics*; D008099:Liver / Q000378:metabolism; D010957:Plasmids
D001053:Apolipoproteins; D001057:Apolipoproteins E; D008079:Lipoproteins, VLDL; D004247:DNA