TRPgamma, a Drosophila TRP-related Subunit, Forms a Regulated Cation Channel With TRPL

Neuron. 2000 Jun;26(3):647-57. doi: 10.1016/s0896-6273(00)81201-5.

Abstract

TRP and TRPL are two light-sensitive cation channel subunits required for the Drosophila photoresponse; however, our understanding of the identities, subunit composition, and function of the light-responsive channels is incomplete. To explain the residual photoresponse that remains in the trp mutant, a third TRP-related subunit has previously been proposed to function with TRPL. Here, we identify such a subunit, TRPgamma. We show that TRPgamma is highly enriched in photoreceptor cells and preferentially heteromultimerizes with TRPL in vitro and in vivo. The N-terminal domain of TRPgamma dominantly suppressed the TRPL-dependent photoresponse, indicating that TRPgamma-TRPL heteromultimers contribute to the photoresponse. While TRPL and TRPgamma homomultimers are constitutively active, we demonstrate that TRPL-TRPgamma heteromultimers form a regulated phospholipase C- (PLC-) stimulated channel.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence / genetics
  • Animals
  • Calcium Channels / genetics
  • Calcium Channels / physiology*
  • Calmodulin-Binding Proteins / genetics
  • Calmodulin-Binding Proteins / metabolism*
  • Cations / metabolism*
  • Drosophila / physiology
  • Drosophila Proteins*
  • Electroretinography
  • Insect Proteins / genetics
  • Insect Proteins / physiology*
  • Ion Channels / genetics
  • Ion Channels / metabolism*
  • Ion Channels / physiology*
  • Light
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Organelles / metabolism
  • Photoreceptor Cells, Invertebrate / metabolism
  • Protein Isoforms / genetics
  • Protein Isoforms / physiology*
  • Retina / radiation effects
  • Transient Receptor Potential Channels

Substances

  • Calcium Channels
  • Calmodulin-Binding Proteins
  • Cations
  • Drosophila Proteins
  • Insect Proteins
  • Ion Channels
  • Membrane Proteins
  • Protein Isoforms
  • TRPgamma protein, Drosophila
  • Transient Receptor Potential Channels
  • trp protein, Drosophila
  • trpl protein, Drosophila

Associated data

  • GENBANK/AJ277967
  • GENBANK/AJ277968