Coassembly of TRP and TRPL produces a distinct store-operated conductance.
The Drosophila retinal-specific protein, TRP (transient receptor potential), is the founding member of a family of store-operated channels (SOCs) conserved from C. elegans to humans. In vitro studies indicate that TRP is a SOC, but that the related retinal protein, TRPL, is constitutively active. In the current work, we report that coexpression of TRP and TRPL leads to a store-operated, outwardly rectifying current distinct from that owing to either TRP or TRPL alone. TRP and TRPL interact directly, indicating that the TRP-TRPL-dependent current is mediated by heteromultimeric association between the two subunits. We propose that the light-activated current in photoreceptor cells is produced by a combination of TRP homo- and TRP-TRPL heteromultimers.
Xu
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Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Li
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Guggino
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Montell
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D000818:Animals; D015220:Calcium Channels / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry; D002478:Cells, Cultured; D004330:Drosophila / Q000737:chemistry / Q000502:physiology; D029721:Drosophila Proteins; D004553:Electric Conductivity; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology; D011233:Precipitin Tests; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary; D050052:TRPC Cation Channels; D050051:Transient Receptor Potential Channels; D015003:Yeasts / Q000737:chemistry / Q000502:physiology
D015220:Calcium Channels; D002148:Calmodulin-Binding Proteins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D050052:TRPC Cation Channels; D050051:Transient Receptor Potential Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; C074192:trpl protein, Drosophila