Identification of a domain in the carboxy terminus of CCK receptor that affects its intracellular trafficking

William Y. Go, Eileen L. Holicky, Elizabeth M. Hadac, Rammohan V. Rao, Laurence J. Miller

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

The carboxy-terminal region of many guanine nucleotide-binding protein (G protein)-coupled receptors contains important regulatory sequences such as an NP(x)(2-3)Y motif, a site of fatty acid acylation, and serine- and threonine-rich domains. The type A CCK receptor contains all of these, yet their significance has not been examined. We have, therefore, constructed a series of receptor site mutants and truncations that interfere with each of these motifs and expressed each in Chinese hamster ovary cells where they were studied for radioligand binding, cell signaling, receptor internalization, and intracellular trafficking. Each construct was synthesized and transported appropriately to the cell surface, where CCK bound with high affinity, elicited an inositol 1,4,5-trisphosphate response, and resulted in internalization and normal trafficking. Thus modification or elimination of each of these established sequence motifs had no substantial effect on any of these parameters of receptor and cellular function. However, an additional construct that truncated the carboxy terminus, eliminating an additional 15-amino-acid segment devoid of any currently recognized sequence motifs, resulted in a marked change in receptor trafficking, with all other parameters of receptor function normal. This mutant receptor construct was delayed at the stage of early endosomes, delaying its progress to the lysosome-enriched perinuclear compartment from the rapid time course followed by wild-type receptor and all of the other constructs. It is proposed that this region of the CCK receptor tail contains a new motif important for intracellular receptor trafficking.

Original languageEnglish (US)
Pages (from-to)G56-G62
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume275
Issue number1 38-1
DOIs
StatePublished - Jul 1998

Keywords

  • Cholecystokinin
  • Endocytosis
  • G protein-coupled receptor
  • Receptor internalization
  • Receptor trafficking

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Identification of a domain in the carboxy terminus of CCK receptor that affects its intracellular trafficking'. Together they form a unique fingerprint.

Cite this