G-protein coupled receptor 55 (GPR55)

Function

• may be involved in hyperalgesia associated with inflammatory & neuropathic pain
• receptor for L-alpha-lysophosphatidylinositol (LPI)
• LPI induces Ca+2 release from intracellular stores via the heterotrimeric G protein GNA13 & RHOA
• cannabinoid receptor
• may play a role in bone physiology by regulating osteoclast number & function

Structure

• belongs to the G-protein coupled receptor 1 family

Compartment

• cell membrane; multi-pass membrane protein

Expression

• expressed in the caudate nucleus & putamen,
• not detected in the hippocampus, thalamus, pons cerebellum, frontal cortex of the brain or in the liver
• expressed in osteoclasts & osteoblasts

Notes

• classification of this protein as a cannabinoid receptor remains a contentious issue due to conflicting pharmacological results

More general terms

• G-protein coupled receptor; serpentine receptor

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=9290
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:9290
• OMIM: https://mirror.omim.org/entry/604107
• UniProt: http://www.uniprot.org/uniprot/Q9Y2T6.html