DAG lipase activity is necessary for TRP channel regulation in Drosophila photoreceptors.
In Drosophila, a phospholipase C-mediated signaling cascade links photoexcitation of rhodopsin to the opening of the TRP/TRPL channels. A lipid product of the cascade, diacylglycerol (DAG) and its metabolite(s), polyunsaturated fatty acids (PUFAs), have both been proposed as potential excitatory messengers. A crucial enzyme in the understanding of this process is likely to be DAG lipase (DAGL). However, DAGLs that might fulfill this role have not been previously identified in any organism. In this work, the Drosophila DAGL gene, inaE, has been identified from mutants that are defective in photoreceptor responses to light. The inaE-encoded protein isoforms show high sequence similarity to known mammalian DAG lipases, exhibit DAG lipase activity in vitro, and are highly expressed in photoreceptors. Analyses of norpA inaE double mutants and severe inaE mutants show that normal DAGL activity is required for the generation of physiologically meaningful photoreceptor responses.
Leung
Hung-Tat
HT
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2054, USA.
Tseng-Crank
Julie
J
Kim
Eunju
E
Mahapatra
Cecon
C
Shino
Shikoh
S
Zhou
Ying
Y
An
Lingling
L
Doerge
Rebecca W
RW
Pak
William L
WL
D000818:Animals; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism*; D010775:Photic Stimulation / Q000379:methods; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology*; D050052:TRPC Cation Channels / Q000502:physiology*
D029721:Drosophila Proteins; D050052:TRPC Cation Channels; D008071:Lipoprotein Lipase