During initial several minutes after fertilization, sea urchin eggs exhibited high rate of respiration which was only slightly inhibited by cyanide. This cyanide-insensitive respiration was inhibited by calcium antagonists, diltiazem and verapamil, and calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphthalensulfonamide hydrochloride (W-7), N-(6-aminohexyl)-1-naphthalenesulfonamide hydrochloride (W-5) and chlorpromazine, which were added within 1 min after insemination. The inhibitory effect of W-7 on cyanide-insensitive respiration was higher than that of W-5. Cyanide-sensitive respiration of fertilized eggs observed after this initial period was not inhibited by these compounds. Ca influx in eggs just after fertilization was inhibited by calcium antagonists but was rather enhanced by calmodulin antagonists. Fertilization-induced stimulation of cyanide-insensitive respiration probably results from calmodulin-dependent reactions which are activated by Ca influx.
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http://dx.doi.org/10.1111/j.1440-169X.1985.00063.x | DOI Listing |
Redox Biol
November 2024
Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY, 10065, USA. Electronic address:
Alternative oxidase (AOX) is an enzyme that transfers electrons from reduced quinone directly to oxygen without proton translocation. When AOX from Ciona intestinalis is xenotopically expressed in mice, it can substitute the combined electron-transferring activity of mitochondrial complexes III/IV. Here, we used brain mitochondria from AOX-expressing mice with such a chimeric respiratory chain to study respiratory control bioenergetic mechanisms.
View Article and Find Full Text PDFUnlabelled: is a ubiquitous environmental pathogen. Despite its remarkable adaptability, little is known about the mechanisms of stress resistance in this bacterium. Here, in a screen for iron-susceptible transposon mutants, we identified a cytochrome that protects against multiple stresses.
View Article and Find Full Text PDFAntioxidants (Basel)
March 2024
Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, 00185 Rome, Italy.
Hydrogen sulfide (HS) and nitric oxide (NO) are long-known inhibitors of terminal oxidases in the respiratory chain. Yet, they exert pivotal signaling roles in physiological processes, and in several bacterial pathogens have been reported to confer resistance against oxidative stress, host immune responses, and antibiotics. , an opportunistic pathogen causing life-threatening infections that are difficult to eradicate, has a highly branched respiratory chain including four terminal oxidases of the haem-copper type (, , , and ) and one oxidase of the -type (cyanide-insensitive oxidase, CIO).
View Article and Find Full Text PDFAppl Environ Microbiol
October 2023
Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
grows as a biofilm under many environmental conditions, and the bacterium can disperse from biofilms via highly regulated, dynamic processes. However, physiologic triggers of biofilm dispersal remain poorly understood. Based on prior literature describing dispersal triggered by forms of starvation, we tested bacterial respiratory inhibitors for biofilm dispersal in two models resembling chronic airway infections.
View Article and Find Full Text PDFSci Rep
June 2023
Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdańsk, ul. A. Abrahama 58, 80-307, Gdańsk, Poland.
Pseudomonads are metabolically flexible and can thrive on different plant hosts. However, the metabolic adaptations required for host promiscuity are unknown. Here, we addressed this knowledge gap by employing RNAseq and comparing transcriptomic responses of Pseudomonas donghuensis P482 to root exudates of two plant hosts: tomato and maize.
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