The human gastrin/cholecystokinin type B receptor gene: alternative splice donor site in exon 4 generates two variant mRNAs.
Gastrin and its carboxyl-terminal homolog cholecystokinin (CCK) exert a variety of biological actions in the brain and gastrointestinal tract that are mediated in part through one or more G protein-coupled receptors which exhibit similar affinity for both peptides. Genomic clones encoding a human gastrin/CCKB receptor were isolated by screening a human EMBL phage library with a partial-length DNA fragment which was based on the nucleotide sequence of the canine gastrin receptor. The gene contained a 1356-bp open reading frame consisting of five exons interrupted by 4 introns and was assigned to human chromosome 11p15.4. A region of exon 4, which encodes a portion of the putative third intracellular loop, appears to be alternatively spliced to yield two different mRNAs, one containing (452 amino acids; long isoform) and the other lacking (447 amino acids; short isoform) the pentapeptide sequence Gly-Gly-Ala-Gly-Pro. The two receptor isoforms may contribute to functional differences in gastrin- and CCK-mediated signal transduction.
Song
I
I
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109.
Brown
D R
DR
Wiltshire
R N
RN
Gantz
I
I
Trent
J M
JM
Yamada
T
T
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D003001:Cloning, Molecular; D017931:DNA Primers; D005091:Exons; D014644:Genetic Variation; D015698:Genomic Library; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis*; D011949:Receptors, Cholecystokinin / Q000096:biosynthesis* / Q000235:genetics*; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D012333:RNA, Messenger; D011949:Receptors, Cholecystokinin