Linked Life Data

16706600

Source:http://linkedlifedata.com/resource/pubmed/id/16706600

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-6-6
pubmed:abstractText
In the vertebrate retina, rods mediate twilight vision and cones mediate daylight vision. Their photoresponse characteristics are different. The light-sensitivity of a cone is 10(2)-10(3) times lower than that of a rod. In addition, the photoresponse time course is much faster in cones. The mechanism characterizing cone photoresponses has not been known mainly because of the difficulty in isolating cones in large quantities to perform biochemistry. Recently, we developed a method to purify cones from carp retina using a density gradient, which made it possible to analyze the differences in the molecular mechanism of phototransduction between rods and cones. The results showed that signal amplification in cones is less effective, which explains the lower light-sensitivity of cones. The results also showed that visual pigment phosphorylation, a quenching mechanism of light-activated visual pigment, is much more rapid in cones than in rods. The rapid phosphorylation in cones is attributed to a very high total kinase activity in cones. Because of this high activity, cone pigment is readily phosphorylated even at very high bleaching levels, which probably explains why cone photoresponses recover quickly. Based on these findings, the molecular mechanisms of the differences in the photoresponse characteristics between rods and cones are outlined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0031-8655
pubmed:author
pubmed:issnType
Print
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19-26
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:articleTitle
Molecular mechanisms characterizing cone photoresponses.
pubmed:affiliation
Graduate School of Frontier Biosciences, Osaka University, Suita, Japan. banaki@fbs.osaka-u.ac.jp
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't