Single base substitution between human intestinal and hepatic apolipoprotein B mRNA detected by ribonuclease cleavage analysis.
The molecular mechanism of human intestinal apolipoprotein (apo) B-48 synthesis has been elucidated by a combination of sequencing of cloned complementary DNAs and RNase cleavage analysis of RNA heteroduplex. All intestinal cDNA clones contained a single C to T base substitution in the codon CAA encoding Gln2153 in apoB-100 cDNA, resulting in a translational stop. One of the our intestinal apoB cDNA clones was polyadenylated 106 bases downstream from the stop codon, possibly producing a 7-kb apoB message in the intestine. RNase cleavage analysis of the RNA heteroduplex between hepatic or intestinal RNA and apoB cDNA-directed anti-sense RNA showed that this single C to U substitution may occur in most of intestinal apoB mRNA. These results suggested that human apoB-48 is mostly produced by apoB mRNA with an in-frame stop codon in the intestine.
Aburatani
H
H
Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo.
Matsumoto
A
A
Ishikawa
T
T
Takaku
F
F
Itakura
H
H
D001055:Apolipoproteins B / Q000096:biosynthesis* / Q000235:genetics; D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D011489:Protein Denaturation; D012313:RNA / Q000032:analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012260:Ribonucleases; D014158:Transcription, Genetic
D001055:Apolipoproteins B; D012333:RNA, Messenger; D012313:RNA; D012260:Ribonucleases