A truncated isoform of human CCK-B/gastrin receptor generated by alternative usage of a novel exon

Biochem Biophys Res Commun. 1995 Mar 8;208(1):230-7. doi: 10.1006/bbrc.1995.1328.


An isoform cDNA of CCK-B/gastrin receptor was isolated from human stomach. This cDNA differed from initially cloned cDNA only in the 5'-end region and encoded a truncated isoform (delta CCK-B) in which the putative N-terminal extracellular domain of the CCK-B/gastrin receptor was completely lost. Isolation of genomic CCK-B/gastrin receptor DNA revealed that this transcript is generated by alternative usage of a novel exon, termed exon 1b. Human stomach expressed both transcripts of delta CCK-B and entire CCK-B/gastrin receptor (CCK-BR), whereas human stomach cancer cell line AGS exclusively expressed delta CCK-B transcripts. Transfection of COS-7 with delta CCK-B cDNA led to the appearance of binding sites for 125I-CCK-8. Its ligand selectivity was different from that of CCK-BR. These results suggest the molecular diversity in CCK-B/gastrin receptor subtypes.

MeSH terms

  • Alternative Splicing*
  • Animals
  • Base Sequence
  • Binding, Competitive
  • Blotting, Southern
  • Cell Line
  • Chlorocebus aethiops
  • DNA / isolation & purification
  • DNA / metabolism
  • DNA Primers
  • DNA, Complementary
  • Exons*
  • Gastric Mucosa / metabolism
  • Gene Expression
  • Humans
  • Kinetics
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis
  • RNA, Messenger / biosynthesis
  • Receptors, Cholecystokinin / biosynthesis*
  • Receptors, Cholecystokinin / metabolism
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / metabolism
  • Restriction Mapping
  • Sincalide / metabolism
  • Transcription, Genetic
  • Transfection


  • DNA Primers
  • DNA, Complementary
  • RNA, Messenger
  • Receptors, Cholecystokinin
  • Recombinant Proteins
  • DNA
  • Sincalide

Associated data

  • GENBANK/S75765
  • GENBANK/S76072