The history of the Drosophila TRP channel: the birth of a new channel superfamily.
Transient receptor potential (TRP) channels are polymodal cellular sensors involved in a wide variety of cellular processes, mainly by changing membrane voltage and increasing cellular Ca(2+). This review outlines in detail the history of the founding member of the TRP family, the Drosophila TRP channel. The field began with a spontaneous mutation in the trp gene that led to a blind mutant during prolonged intense light. It was this mutant that allowed for the discovery of the first TRP channels. A combination of electrophysiological, biochemical, Ca(2+) measurements, and genetic studies in flies and in other invertebrates pointed to TRP as a novel phosphoinositide-regulated and Ca(2+)-permeable channel. The cloning and sequencing of the trp gene provided its molecular identity. These seminal findings led to the isolation of the first mammalian homologues of the Drosophila TRP channels. We now know that TRP channel proteins are conserved through evolution and are found in most organisms, tissues, and cell-types. The TRP channel superfamily is classified into seven related subfamilies: TRPC, TRPM, TRPV, TRPA, TRPP, TRPML, and TRPN. A great deal is known today about participation of TRP channels in many biological processes, including initiation of pain, thermoregulation, salivary fluid secretion, inflammation, cardiovascular regulation, smooth muscle tone, pressure regulation, Ca(2+) and Mg(2+) homeostasis, and lysosomal function. The native Drosophila photoreceptor cells, where the founding member of the TRP channels superfamily was found, is still a useful preparation to study basic features of this remarkable channel.
Department of Medical Neurobiology, The Institute of Medical Research Israel-Canada, The Edmond and Lily Safra Center for Brain Sciences and the Kühne Minerva Center for Studies of Visual Transduction, Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel. baruchm@ekmd.huji.ac.il
Baruch
B
Minke
D000818:Animals; D015220:Calcium Channels / Q000737:chemistry* / Q000266:history / Q000502:physiology; D004330:Drosophila / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry* / Q000266:history / Q000502:physiology; D019143:Evolution, Molecular; D005260:Female; D049673:History, 20th Century; D006801:Humans; D008322:Mammals / Q000378:metabolism; D023421:Models, Animal; D050051:Transient Receptor Potential Channels / Q000737:chemistry* / Q000266:history / Q000502:physiology
D015220:Calcium Channels; D029721:Drosophila Proteins; D050051:Transient Receptor Potential Channels; C063169:trp protein, Drosophila