PMID- 10419536
OWN - NLM
STAT- MEDLINE
DCOM- 19990819
LR  - 20220227
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 31
DP  - 1999 Jul 30
TI  - Calmodulin binding to G protein-coupling domain of opioid receptors.
PG  - 22081-8
AB  - The ubiquitous intracellular Ca(2+) sensor calmodulin (CaM) regulates numerous
      proteins involved in cellular signaling of G protein-coupled receptors, but most 
      known interactions between GPCRs and CaM occur downstream of the receptor. Using 
      a sequence-based motif search, we have identified the third intracellular loop of
      the opioid receptor family as a possible direct contact point for interaction
      with CaM, in addition to its established role in G protein activation. Peptides
      derived from the third intracellular loop of the mu-opioid (OP(3)) receptor
      strongly bound CaM and were able to reduce binding interactions observed between 
      CaM and immunopurified OP(3) receptor. Functionally, CaM reduced basal and
      agonist-stimulated (35)S-labeled guanosine 5'-3-O-(thio)triphosphate
      incorporation, a measure of G protein activation, in membranes containing
      recombinant OP(3) receptor. Changes in CaM membrane levels as a result of
      overexpression or antisense CaM suppression inversely affected basal and
      agonist-induced G protein activation. The ability of CaM to abolish high affinity
      binding sites of an agonist at OP(3) further supports the hypothesis of a direct 
      interaction between CaM and opioid receptors. An OP(3) receptor mutant with a
      Lys(273) --> Ala substitution (K273A-OP(3)), an amino acid predicted to play a
      critical role in CaM binding based on motif structure, was found to be unaffected
      by changes in CaM levels but coupled more efficiently to G proteins than the
      wild-type receptor. Stimulation of both the OP(1) (delta-opioid) and OP(3)
      wild-type receptors, but not the K273A-OP(3) mutant, induced release of CaM from 
      the plasma membrane. These results suggest that CaM directly competes with G
      proteins for binding to opioid receptors and that CaM may itself serve as an
      independent second messenger molecule that is released upon receptor stimulation.
FAU - Wang, D
AU  - Wang D
AD  - Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry and the
      Center for the Neurobiology of Drug Addiction, University of California San
      Francisco, San Francisco, California 94143-0446, USA.
FAU - Sadee, W
AU  - Sadee W
FAU - Quillan, J M
AU  - Quillan JM
LA  - eng
GR  - DA04166/DA/NIDA NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Calmodulin)
RN  - 0 (Peptide Fragments)
RN  - 0 (Receptors, Opioid, mu)
RN  - 0 (Recombinant Proteins)
RN  - 36B82AMQ7N (Naloxone)
RN  - 76I7G6D29C (Morphine)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Binding, Competitive
MH  - Biotinylation
MH  - Calmodulin/*metabolism
MH  - Cell Line
MH  - GTP-Binding Proteins/*metabolism
MH  - Humans
MH  - Kinetics
MH  - Mice
MH  - Molecular Sequence Data
MH  - Morphine/pharmacology
MH  - Mutagenesis, Site-Directed
MH  - Naloxone/pharmacokinetics
MH  - Peptide Fragments/chemistry/metabolism
MH  - Rats
MH  - Receptors, Opioid, mu/*chemistry/isolation & purification/*metabolism
MH  - Recombinant Proteins/chemistry/isolation & purification/metabolism
MH  - Sequence Alignment
MH  - Sequence Homology, Amino Acid
MH  - Transfection
EDAT- 1999/07/27 00:00
MHDA- 1999/07/27 00:01
CRDT- 1999/07/27 00:00
PHST- 1999/07/27 00:00 [pubmed]
PHST- 1999/07/27 00:01 [medline]
PHST- 1999/07/27 00:00 [entrez]
AID - 10.1074/jbc.274.31.22081 [doi]
AID - S0021-9258(19)72489-2 [pii]
PST - ppublish
SO  - J Biol Chem. 1999 Jul 30;274(31):22081-8. doi: 10.1074/jbc.274.31.22081.