Cell-nonautonomous function of ceramidase in photoreceptor homeostasis
AuthorsAcharya, Jairaj K.
Rawat, Satinder S.
Sanxaridis, Parthena D.
Brodsky, Michael H.
Animals, Genetically Modified
Gene Expression Regulation, Developmental
Photoreceptor Cells, Invertebrate
Genetics and Genomics
MetadataShow full item record
AbstractNeutral ceramidase, a key enzyme of sphingolipid metabolism, hydrolyzes ceramide to sphingosine. These sphingolipids are critical structural components of cell membranes and act as second messengers in diverse signal transduction cascades. Here, we have isolated and characterized functional null mutants of Drosophila ceramidase. We show that secreted ceramidase functions in a cell-nonautonomous manner to maintain photoreceptor homeostasis. In the absence of ceramidase, photoreceptors degenerate in a light-dependent manner, are defective in normal endocytic turnover of rhodopsin, and do not respond to light stimulus. Consistent with a cell-nonautonomous function, overexpression of ceramidase in tissues distant from photoreceptors suppresses photoreceptor degeneration in an arrestin mutant and facilitates membrane turnover in a rhodopsin null mutant. Furthermore, our results show that secreted ceramidase is internalized and localizes to endosomes. Our findings establish a role for a secreted sphingolipid enzyme in the regulation of photoreceptor structure and function.
SourceNeuron. 2008 Jan 10;57(1):69-79. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/44120
Related ResourcesLink to Article in PubMed