Ribonucleotide reductase in an anoxia tolerant vertebrate, the crucian carp
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چکیده
منابع مشابه
Studies of Ribonucleotide Reductase in Crucian Carp—An Oxygen Dependent Enzyme in an Anoxia Tolerant Vertebrate
The enzyme ribonucleotide reductase (RNR) catalyzes the conversion of ribonucleotides to deoxyribonucleotides, the precursors for DNA. RNR requires a thiyl radical to activate the substrate. In RNR of eukaryotes (class Ia RNR), this radical originates from a tyrosyl radical formed in reaction with oxygen (O(2)) and a ferrous di-iron center in RNR. The crucian carp (Carassius carassius) is one o...
متن کاملSeasonality of dihydropyridine receptor binding in the heart of an anoxia-tolerant vertebrate, the crucian carp (Carassius carassius L.).
Prolonged anoxia tolerance of facultative anaerobes is based on metabolic depression and thus on controlled reduction of energy-utilizing processes. One proposed survival mechanism is the closing of ion channels to decrease energetic cost of ion pumping (Hochachka PW. Science 231: 234-241, 1986). To test this hypothesis, the involvement of L-type Ca2+ channels in seasonal anoxia tolerance of th...
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In the brain, oxygen is required for both the synthesis and the degradation of monoamine transmitters, so monoaminergic systems can be expected to be strongly affected by anoxia. However, crucian carp {Carassius carassius L.) may survive anoxia for many days or even weeks. In the present study, crucian carp were exposed to anoxia for 22, 76, and 160 h at 8°C. All survived and were found to excr...
متن کاملCrucian carp heart performance during anoxia and acidosis
The crucian carp (Carassius carassius L.) exhibits the unique ability among vertebrates to maintain cardiac performance at normoxic levels during prolonged anoxia exposure. This thesis investigates the hypothesis that this phenomenon is possible because the heart likely never experiences an extracellular pH below 7.4 due to the fish’s exclusive trait of converting lactate and H ions to ethanol....
متن کاملCell proliferation and gill morphology in anoxic crucian carp.
Is DNA replication/cell proliferation in vertebrates possible during anoxia? The oxygen dependence of ribonucleotide reductase (RNR) could lead to a stop in DNA synthesis, thereby making anoxic DNA replication impossible. We have studied this question in an anoxia-tolerant vertebrate, the crucian carp (Carassius carassius), by examining 5'-bromo-2'-deoxyuridine incorporation and proliferating c...
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ژورنال
عنوان ژورنال: The FASEB Journal
سال: 2009
ISSN: 0892-6638,1530-6860
DOI: 10.1096/fasebj.23.1_supplement.598.11