Linked Life Data

8731341

Source:http://linkedlifedata.com/resource/pubmed/id/8731341

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-12-3
pubmed:abstractText
The marine bioluminescent dinoflagellate Gonyaulax polyedra is capable of producing various indoleamines. The first enzyme in their formation, tryptophan hydroxylase, exhibits a high-amplitude circadian rhythm with a maximum during photophase. Hydroxyindole-O-methyltransferase shows a biphasic pattern with a major maximum during scotophase. 5-Methoxylated indoleamines, such as melatonin and 5-methoxytryptamine, peak at the beginning and in the second half of scotophase, respectively. A drop in temperature from 20 to 15 degrees C leads to dramatic increases of melatonin, up to more than 50 ng/mg protein. This effect may explain why a lower temperature sensitizes this organism to photoperiodic, indoleamine-mediated induction of asexual cysts. Melatonin can be catabolized either enzymatically or non-enzymatically. The non-enzymatic pathway involves free radicals, e.g., photooxidant cation radicals, and leads to the formation of N1-acetyl-N2- formyl-5-methoxykynuramine. Enzymatic catabolism comprises deacetylation to 5-methoxytryptamine and formation of 5-methoxytryptophol. 5-Methoxytryptamine represents a key substance acting as a stimulator of bioluminescence and a mediator of the encystment response. It opens proton channels in the membrane of an intracellular acidic vacuole system which is loaded by the action of a V-type ATPase, as shown by experiments using bafilomycin A1.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0100-879X
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
119-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Chronobiology of indoleamines in the dinoflagellate Gonyaulax polyedra: metabolism and effects related to circadian rhythmicity and photoperiodism.
pubmed:affiliation
Zoologisches Institut, Universitaet Goettingen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't