title: Apolipoprotein B-48 is the product of a messenger RNA with an organ-specific in-frame stop codon.
abstract: The primary structure of human apolipoprotein (apo) B-48 has been deduced and shown by a combination of DNA excess hybridization, sequencing of tryptic peptides, cloned complementary DNAs, and intestinal messenger RNAs (mRNAs) to be the product of an intestinal mRNA with an in-frame UAA stop codon resulting from a C to U change in the codon CAA encoding Gln2153 in apoB-100 mRNA. The carboxyl-terminal Ile2152 of apoB-48 purified from chylous ascites fluid has apparently been cleaved from the initial translation product, leaving Met2151 as the new carboxyl-terminus. These data indicate that approximately 85% of the intestinal mRNAs terminate within approximately 0.1 to 1.0 kilobase downstream from the stop codon. The other approximately 15% have lengths similar to hepatic apoB-100 mRNA even though they have the same in-frame stop codon. The organ-specific introduction of a stop codon to a mRNA appears unprecedented and might have implications for cryptic polyadenylation signal recognition and RNA processing.
authors: Department of Cell Biology, Baylor College of Medicine, Houston, TX 77030.
authors: S H
authors: SH
authors: Chen
authors: G
authors: G
authors: Habib
authors: C Y
authors: CY
authors: Yang
authors: Z W
authors: ZW
authors: Gu
authors: B R
authors: BR
authors: Lee
authors: S A
authors: SA
authors: Weng
authors: S R
authors: SR
authors: Silberman
authors: S J
authors: SJ
authors: Cai
authors: J P
authors: JP
authors: Deslypere
authors: M
authors: M
authors: Rosseneu
mesh_terms: D000595:Amino Acid Sequence; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002915:Chylous Ascites / Q000378:metabolism; D003062:Codon; D004247:DNA / Q000235:genetics; D006801:Humans; D007421:Intestine, Small / Q000032:analysis; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010446:Peptide Fragments; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D014357:Trypsin / Q000378:metabolism
chemical_list: D053283:Apolipoprotein B-48; D001055:Apolipoproteins B; D003062:Codon; D010446:Peptide Fragments; D012333:RNA, Messenger; D004247:DNA; D014357:Trypsin