ISSN:
1432-1351
Keywords:
Rhabdomeral membrane
;
Turnover
;
Diacylglycerols
;
Transcription
;
Protein kinase Cs
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract 1. A previous study implies that diacylglycerols (DAGs) released by the phototransduction cascade in photoreceptors of a crab, Leptograpsus, activate protein kinase Cs (PKCs). PKCs were suggested to phosphorylate nuclear proteins that regulate the transcription of rhabdomeral membrane precursors. 2. We show that a transcription inhibitor, actinomycin D, reduces the rhabdomeral renewal induced by a diacylglycerol lipase inhibitor, U-57908, but does not eliminate it. 3. Within the particular experimental protocol, rhabdomeral maintenance and renewal by controls are inhibited by actinomycin D in an absence of U-57908. 4. We conclude that although rhabdomeral renewal induced by PKC activation involves the regulation of transcription, multiple pathways are implicated. 5. An alternative route for the degradation of DAGs by phosphorylation is eliminated because a specific inhibitor of DAG kinases, R-59022, exerts no effect. 6. U-57908 promotes photoreceptor shrinkage which is not compromised by actinomycin D. Shrinkage occurs independently of rhabdomeral renewal, suggesting a further consequence of PKC activation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00192724
