title: A transient receptor potential channel expressed in taste receptor cells.
abstract: We used differential screening of cDNAs from individual taste receptor cells to identify candidate taste transduction elements in mice. Among the differentially expressed clones, one encoded Trpm5, a member of the mammalian family of transient receptor potential (TRP) channels. We found Trpm5 to be expressed in a restricted manner, with particularly high levels in taste tissue. In taste cells, Trpm5 was coexpressed with taste-signaling molecules such as alpha-gustducin, Ggamma13, phospholipase C-beta2 (PLC-beta2) and inositol 1,4,5-trisphosphate receptor type III (IP3R3). Our heterologous expression studies of Trpm5 indicate that it functions as a cationic channel that is gated when internal calcium stores are depleted. Trpm5 may be responsible for capacitative calcium entry in taste receptor cells that respond to bitter and/or sweet compounds.
mesh_terms: D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D006224:Cricetinae; D015870:Gene Expression; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007527:Isoenzymes / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D009865:Oocytes / Q000502:physiology; D054799:Phospholipase C beta; D012333:RNA, Messenger / Q000032:analysis; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D050053:TRPM Cation Channels; D013649:Taste / Q000502:physiology*; D013650:Taste Buds / Q000502:physiology*; D015293:Transducin / Q000235:genetics; D010738:Type C Phospholipases / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D050053:TRPM Cation Channels; C498617:Trpm5 protein, mouse; C075192:gustducin; D010738:Type C Phospholipases; D054799:Phospholipase C beta; C518037:Plcb2 protein, mouse; C518038:Plcb2 protein, rat; D015293:Transducin; D002118:Calcium