Distinct regions of C-terminus of the high affinity neurotensin receptor mediate the functional coupling with pertussis toxin sensitive and insensitive G-proteins.
The functional coupling of C-terminally truncated mutants of the high affinity rat neurotensin (NT) receptor (NTS1) was characterized in transfected Chinese hamster ovary cells. On cells expressing NTRDelta372 (truncated NTS1 lacking the entire 52 amino acid C-terminus), NT failed to promote [(35)S]guanosine 5'-[gamma-(35)S]triphosphate binding whereas a robust pertussis toxin (PTx) sensitive response was observed in cells expressing a partially truncated receptor (NTRDelta401 lacking the last 23 residues). Similar results were obtained when measuring the ability of NT to induce the production of arachidonic acid. Since neither deletions impaired the NT-induced phosphoinositide hydrolysis, these results indicate that the membrane proximal region of the C-terminus is specifically involved in the functional coupling of the receptor with PTx sensitive G-proteins. This region was also found to be involved in the control of receptor internalization. However, PTx failed to impair internalization, indicating that these two properties are not directly related.
Najimi
Mustapha
M
Laboratoire de Pharmacologie Exprimentale (FARL), Département de Physiologie et de Pharmacologie, Université catholique de Louvain 54.10, Avenue Hippocrate 54, B-1200, Brussels, Belgium.
Gailly
Philippe
P
Maloteaux
Jean Marie
JM
Hermans
Emmanuel
E
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000187:drug effects / Q000378:metabolism; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D009496:Neurotensin / Q000494:pharmacology; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D037342:Pertussis Toxin; D010716:Phosphatidylinositols / Q000378:metabolism; D021381:Protein Transport; D051381:Rats; D018028:Receptors, Neurotensin / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D010446:Peptide Fragments; D010716:Phosphatidylinositols; D018028:Receptors, Neurotensin; D011994:Recombinant Proteins; D010566:Virulence Factors, Bordetella; C114036:neurotensin type 1 receptor; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D009496:Neurotensin; D037342:Pertussis Toxin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins