Immunolocalization of Drosophila eye‐specific diacylgylcerol kinase, rdgA , which is essential for the maintenance of the photoreceptor

Abstract

The Drosophila retinal degeneration A (rdgA) mutant has photoreceptor cells that degenerate within a week after eclosion. The degeneration starts with the disruption of the subrhabdomeric cisternae (SRC), which are the organelles essential for the transport of phospholipids to the photoreceptive membranes. Our previous biochemical and molecular studies suggested that the rdgA gene encodes an eye‐specific diacylglycerol kinase (DGK). In this study, we show that retinal degeneration is prevented by the introduction of the eye‐DGK gene in the rdgA mutant genome, suggesting that the DGK activity is crucial for the maintenance of the photoreceptor. Furthermore, by immunohistochemical analysis, we have demonstrated that the rdgA protein is predominantly associated with the SRC, suggesting that the conversion from diacylglycerol (DG) to phosphatidic acid (PA) most actively occurs in SRC. The analysis of the eyes of mutants homozygous for rdgA and eye‐protein kinase C mutations indicates that retinal degeneration is caused by the deficiency of PA rather than excessive accumulation of DG. From these data, we conclude that the production of PA in the SRC membranes is essential for the maintenance of the photoreceptor. © 1997 John Wiley & Sons, Inc. J Neurobiol 32: 695–706, 1997

Mammalian Diacylglycerol Kinases, a Family of Lipid Kinases with Signaling Functions

“…They found a mutation in the ATP binding site that would presumably account for the loss of DGK activity. This group later showed that the rdgA phenotype could be rescued by introducing wild-type rdgA into the mutant strain (64). Together, these studies demonstrate that formation of phosphatidic acid by dDGK2 is necessary for proper visual signaling in Drosophila.…”

Quantitative Proteomics of a Presymptomatic A53T α-Synuclein Drosophila Model of Parkinson Disease

“…Drosophila chaoptin mutants display remarkable membrane abnormalities (49). The protein encoded by retinal degeneration A (rdgA) is associated with the transport of phospholipids to the photoreceptive membranes, and the Drosophila rdgA mutant induces degeneration in photoreceptor cells within a week posteclosion (50). Down-regulation of both chaoptic and rdgA at the protein level suggests disruption of the structural integrity of neuronal cell membranes that could lead to failure in cell communications and subsequent malfunction of cellular processes.…”

O-Linked-N-acetylglucosamine on extracellular protein domains mediates epithelial cell–matrix interactions

“…Th e second-instar larvae were dissected between the A6 and A7 segments, fi xed with 4 % paraformaldehyde and 1 % glutaraldehyde in cacodylate buff er (pH 7.4) 39 , and observed by transmission electron microscopy 40 .…”