Linked Life Data

11457836

Source:http://linkedlifedata.com/resource/pubmed/id/11457836

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2001-9-10
pubmed:abstractText
The mu opioid receptor (MOR) plays a central role in mediating acute and chronic effects of narcotic drugs. Three rare single nucleotide polymorphisms in the hMOR gene have been identified that cause amino acid substitutions in the third intracellular (i3) loop of MOR (R260H, R265H, and S268P). Genotyping 252 individuals of the Coriell collection identified one allele encoding the R265H-MOR variant and a new variant encoding D274N-MOR. Variants R260H-, R265H-, and S268P-MOR were constructed and transfected into HEK293 cells. Morphine stimulated G protein coupling of the three receptor variants to a maximal level approaching that of wild type MOR. In contrast, spontaneous, agonist-independent (basal) MOR signaling, proposed to play a role in opioid tolerance and dependence, was significantly reduced for R260H- and R265H-MOR. Moreover, domains within the i3 loop of MOR have been shown to interact with both G proteins and calmodulin (CaM). CaM binding was deficient for variants R265H- and S268P-MOR, suggesting that domains for G protein coupling and CaM binding overlap partially. Morphine pretreatment significantly enhanced basal G protein coupling of wild type MOR, which is thought to result from release of CaM. In contrast basal G protein coupling activity of the three variants was unaffected by morphine pretreatment consistent with diminished CaM regulation, low basal activity, or both. In conclusion, each of the three single nucleotide polymorphisms mapping to the i3 loop of MOR caused substantial changes in basal G protein coupling, CaM binding, or both. Carriers of the mutant alleles might display altered responses to narcotic analgesics.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34624-30
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Single nucleotide polymorphisms in the human mu opioid receptor gene alter basal G protein coupling and calmodulin binding.
pubmed:affiliation
Department of Biopharmaceutical Sciences and Pharmaceutical Chemistry, University of California, San Francisco, California 94143-0446, USA.
pubmed:publicationType
Journal Article