Linked Life Data

8823934

Source:http://linkedlifedata.com/resource/pubmed/id/8823934

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1996-12-3
pubmed:abstractText
Vertebrate and invertebrate photoreceptors shed their photosensitive membrane on a daily basis. Although we have detailed knowledge of the morphology of the disc shedding and renewal process in vertebrate photoreceptors, and of the turnover of rhabdom in invertebrate photoreceptors, we know relatively little about the molecular mechanisms whereby these processes are triggered by light and/or by circadian efferent input to the retina. We have used the horseshoe crab, Limulus polyphemus, as a model system to unravel the molecular means by which the trigger light is communicated to the intracellular machinery responsible for the daily breakdown of the photosensitive membrane. Phorbol esters, potent and specific activators of protein kinase C (PKC), induce a robust burst of rhabdom shedding when injected subretinally into the compound lateral eye of Limulus. This occurs in the absence of the light trigger normally required to initiate shedding in the lateral eye at dawn, suggesting that PKC may play a role in the light triggering of rhabdom shedding. Diacylglycerol (DAG) analogs were also found to elicit rhabdom shedding in the lateral eye without a light trigger, but at uncharacteristically high concentrations. However, injecting inositol trisphosphate (InsP3) and DAG analog simultaneously results in a tenfold decrease in the concentration of DAG analog required to initiate a shedding event. Immunohistochemical screening for PKC in the lateral eye shows that two isozymes (PKC beta II and PKC zeta) are co-localized to the retinular cell rhabdom. Taken together, these data suggest that light triggers rhabdom shedding at dawn via a classical Ca(2+)-sensitive PKC, similar to PKC beta II, which is activated synergistically by the light-evoked production of DAG and InsP3.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1011-1344
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-52
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Dawn, diacylglycerol, calcium, and protein kinase C--the retinal wrecking crew. A signal transduction cascade for rhabdom shedding in the Limulus eye.
pubmed:affiliation
Institute for Sensory Research, Syracuse University, NY 13244-5290, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't