Related Experiment Video
Updated: Aug 8, 2026

Methods to Discover Alternative Promoter Usage and Transcriptional Regulation of Murine Bcrp1
Published on: May 27, 2016
A truncated isoform of human CCK-B/gastrin receptor generated by alternative usage of a novel exon
1Molecular Medicine Research Laboratories, Yamanouchi Pharmaceutical Co. Ltd, Tukuba-city, Japan.
Abstract:
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.
Related Concept Videos
G-protein Coupled Receptors
Enzyme-linked Receptors
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...

