Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Low temperatures and high hydrostatic pressures are typical of the deep sea. The effects of these parameters on transmembrane signal transduction were determined through a study of the A1 adenosine receptor-inhibitory guanine nucleotide binding protein-adenylyl cyclase system in brain membranes of the bathyal teleost fish, Antimora rostrata (Moridae). The components of this system were analyzed at 5°C and 1 atm, and the role of the A1 receptor in the modulation of adenylyl cyclase was determined. The A1 selective radioligand N6-[3H]cyclohexyladenosine bound saturably, reversibly, and with high affinity. The Kd of N6-[3H]cyclohexyladenosine estimated from kinetic measurements was 1.11 nM; the Kd determined from equilibrium binding was 4.86 nM. [32P]ADP-ribosylation of brain membranes by pertussis toxin labeled substrates with apparent molecular masses of 39,000 to 41,000 Da. Basal adenylyl cyclase activity was inhibited in a concentration-dependent manner by the A1 adenosine receptor agonist N6-cyclopentyladenosine (IC50 = 5.08 μM). The inhibition of adenylyl cyclase activity was dependent upon GTP. Basal adenylyl cyclase activity was unaffected by 272 atm of pressure. The efficacy of 100 μM N6-cyclopentyladenosine as an inhibitor of adenylyl cyclase was the same at atmospheric pressure and at 272 atm. The inhibition of adenylyl cyclase by the agonist 5'-N-ethylcarboxamidoadenosine (100 μM) at 272 atm was twice that observed at atmospheric pressure. Although consideration of the effects of low temperature and high hydrostatic pressure on acyl chain order suggest that deep-sea conditions will perturb membrane function, signal transduction by the A1 receptor system of the bathyal fish A. rostrata is not disrupted by deep-sea conditions.
Low temperatures and high hydrostatic pressures are typical of the deep sea. The effects of these parameters on transmembrane signal transduction were determined through a study of the A1 adenosine receptor-inhibitory guanine nucleotide binding protein-adenylyl cyclase system in brain membranes of the bathyal teleost fish, Antimora rostrata (Moridae). The components of this system were analyzed at 5°C and 1 atm, and the role of the A1 receptor in the modulation of adenylyl cyclase was determined. The A1 selective radioligand N6-[3H]cyclohexyladenosine bound saturably, reversibly, and with high affinity. The Kd of N6-[3H]cyclohexyladenosine estimated from kinetic measurements was 1.11 nM; the Kd determined from equilibrium binding was 4.86 nM. [32P]ADP-ribosylation of brain membranes by pertussis toxin labeled substrates with apparent molecular masses of 39,000 to 41,000 Da. Basal adenylyl cyclase activity was inhibited in a concentration-dependent manner by the A1 adenosine receptor agonist N6-cyclopentyladenosine (IC50 = 5.08 μM). The inhibition of adenylyl cyclase activity was dependent upon GTP. Basal adenylyl cyclase activity was unaffected by 272 atm of pressure. The efficacy of 100 μM N6-cyclopentyladenosine as an inhibitor of adenylyl cyclase was the same at atmospheric pressure and at 272 atm. The inhibition of adenylyl cyclase by the agonist 5'-N-ethylcarboxamidoadenosine (100 μM) at 272 atm was twice that observed at atmospheric pressure. Although consideration of the effects of low temperature and high hydrostatic pressure on acyl chain order suggest that deep-sea conditions will perturb membrane function, signal transduction by the A1 receptor system of the bathyal fish A. rostrata is not disrupted by deep-sea conditions.
Deep-sea ecosystems contain unique endemic species whose distributions show strong vertical patterning in the case of pelagic animals and sharp horizontal patterning in the case of benthic animals living in or near the deep-sea hydothermal vents. This review discusses the biochemical adaptations that enable deep-sea animals to exploit diverse deep-sea habitats and that help establish biogeographic patterning in the deep-sea. The abilities of deep-sea animals to tolerate the pressure and temperature conditions of deep-sea habitats are due to pervasive adaptations at the biochemical level: enzymes exhibit reduced perturbation of function by pressure, membranes have fluidities adapted to deep-sea pressures and temperatures, and proteins show enhanced structural stability relative to homologous proteins from cold-adapted shallow-living species. Animals from the warmest habitable regions of hydrothermal vent ecosystems have enzymes and mitochondria adapted to high pressure and relatively high temperatures. The low metabolic rates of bathypelagic fishes correlate with greatly reduced capacities for ATP turnover in locomotory muscle. Reduced light and food availability in bathypelagic regions select for low rates of energy expenditure in locomotory activity. Deep-sea animals thus reflect the importance of biochemical adaptations in establishing species distribution patterns and appropriate rates of metabolic turnover in different ecosystems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.