Molecular cloning, developmental expression and pharmacological characterization of the CCKB/gastrin receptor in the calf pancreas

Eur J Pharmacol. 1996 Feb 15;297(1-2):165-79. doi: 10.1016/0014-2999(95)00737-7.

Abstract

We have cloned the calf predominant pancreatic cholecystokinin B (CCKB)/gastrin receptor cDNA. It encodes a 454 amino acid protein with 90% identity with the CCKB/gastrin receptor cloned in other species and tissues. However, the calf pancreatic CCKB/gastrin receptor contains a pentapeptide cassette within the third intracellular loop which is absent in the cloned human brain and stomach receptor. Quantification of the CCKB/gastrin receptor mRNA levels by reverse transcription polymerase chain reaction demonstrated the same level of transcripts at birth, +7 and +28 days. On the other hand, binding study with pancreatic membranes showing a dramatic increase (600-fold) in the number of CCKB/gastrin receptor sites between at birth and +28 days indicates that the development of the calf pancreatic CCKB/gastrin receptor occurs during the first 4 weeks of post-natal life. COS monkey cells (COS-7 cells) transiently transfected by the cloned cDNA exhibit binding of 125I-Bolton-Hunter-[Thr28,Ahx31]CCK-(25-33) and 125I-Bolton-Hunter-[Leu15]human gastrin-(2-17) to two affinity classes of sites. Kd values of the high affinity binding components indicate a 4-fold higher affinity of the receptor for sulfated gastrin than for CCK. Finally, the recombinant receptor is coupled to G proteins and [Ca2+]i mobilization, and is expressed as a glycoprotein of 82 kDa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cattle
  • Cell Line
  • Cloning, Molecular
  • GTP-Binding Proteins / metabolism
  • Gene Expression Regulation, Developmental / physiology*
  • Molecular Sequence Data
  • Open Reading Frames
  • Pancreas / drug effects
  • Pancreas / growth & development
  • Pancreas / metabolism*
  • Polymerase Chain Reaction
  • RNA, Messenger / biosynthesis
  • Radioligand Assay
  • Receptors, Cholecystokinin / biosynthesis
  • Receptors, Cholecystokinin / genetics
  • Receptors, Cholecystokinin / metabolism*
  • Transfection

Substances

  • RNA, Messenger
  • Receptors, Cholecystokinin
  • GTP-Binding Proteins

Associated data

  • GENBANK/S83090