Effect of inhibitors of the respiratory chain and oxidative phosphorylation on the endogenous respiration of the sea-urchin Lytechinus variegatus spermatozoa

Author(s):  
Rubens Rosa ◽  
Dario Ocampos ◽  
Omar Crivellaro ◽  
Metry Bacila
Biologija ◽  
2018 ◽  
Vol 64 (3) ◽  
Author(s):  
Daria M. Dudikova ◽  
Nina O. Vrynchanu ◽  
Valentyna I. Nosar

Derivatives of 4-(1-adamantyl)-phenol are a promising class of antimicrobials affecting the structural integrity and functions of the bacterial cell membrane. The functioning of Pseudomonas aeruginosa respiratory chain and related system of oxidative phosphorylation was investigated before and after treatment with a derivative of 4-(1-adamantyl)-phenol (compound KVM-97). Oxygen consumption was measured polarographically with a Clark-type oxygen electrode. KVM-97 was tested at 0.5× and 1.0× MIC (minimum inhibitory concentration). Specific substrates of the respiratory chain (either 3.0 mM glutamate with 2.0 mM malonate or 3.0 mM succinate with 5.0 μM rotenone) were used. All reactions were stimulated by addition of ADP (0.2 mmol). It was found that at tested concentrations, KVM-97 inhibited the endogenous respiration and substrate oxidation in P. aeruginosa cells. The inhibiting effect was dose-dependent and more pronounced with succinate oxidation rather than glutamate oxidation. The respiratory control index value (RCI) in compound-treated cells was in average 1.5 times lower compared to the intact cells. The decrease in the RCI was related to changing the oxygen uptake rates in state 3 and state 4, which indicate the uncoupling of respiration and oxidative phosphorylation. The data obtained showed that 4-(1-adamantyl)-phenol derivative inhibits oxygen consumption and has uncoupling effects in P. aeruginosa cells.


Aquaculture ◽  
2006 ◽  
Vol 254 (1-4) ◽  
pp. 483-495 ◽  
Author(s):  
Hugh Hammer ◽  
Stephen Watts ◽  
Addison Lawrence ◽  
John Lawrence ◽  
Renee Desmond

2021 ◽  
Vol 118 (39) ◽  
pp. e2106950118
Author(s):  
Johannes F. Hevler ◽  
Riccardo Zenezeni Chiozzi ◽  
Alfredo Cabrera-Orefice ◽  
Ulrich Brandt ◽  
Susanne Arnold ◽  
...  

Combining mass spectrometry–based chemical cross-linking and complexome profiling, we analyzed the interactome of heart mitochondria. We focused on complexes of oxidative phosphorylation and found that dimeric apoptosis-inducing factor 1 (AIFM1) forms a defined complex with ∼10% of monomeric cytochrome c oxidase (COX) but hardly interacts with respiratory chain supercomplexes. Multiple AIFM1 intercross-links engaging six different COX subunits provided structural restraints to build a detailed atomic model of the COX-AIFM12 complex (PDBDEV_00000092). An application of two complementary proteomic approaches thus provided unexpected insight into the macromolecular organization of the mitochondrial complexome. Our structural model excludes direct electron transfer between AIFM1 and COX. Notably, however, the binding site of cytochrome c remains accessible, allowing formation of a ternary complex. The discovery of the previously overlooked COX-AIFM12 complex and clues provided by the structural model hint at potential roles of AIFM1 in oxidative phosphorylation biogenesis and in programmed cell death.


Development ◽  
1989 ◽  
Vol 106 (2) ◽  
pp. 355-365 ◽  
Author(s):  
G.M. Wessel ◽  
W. Zhang ◽  
C.R. Tomlinson ◽  
W.J. Lennarz ◽  
W.H. Klein

The influence of the extracellular matrix (ECM) on differential gene expression during sea urchin development was explored using cell-type-specific cDNA probes. The ECM of three species of sea urchin, Strongylocentrotus purpuratus, Lytechinus variegatus and Lytechinus pictus, was disrupted with the lathrytic agent beta-aminopropionitrile (BAPN), which inhibits collagen deposition in the ECM and arrests gastrulation (Wessel & McClay, Devl Biol. 121: 149, 1987). The levels of several mRNAs (Spec 1, Spec 2, CyIIa actin, CyIIIa actin and collagen in S. purpuratus, and metallothionine, ubiquitin and LpS3 in L. pictus and L. variegatus) were compared in BAPN-treated and control embryos. These mRNAs accumulated normally during BAPN treatment, even though the embryos did not gastrulate. To determine if the expression of any gene product is sensitive to ECM disruption, a differential cDNA screen compared poly (A+) RNA from BAPN-arrested and control embryos in Lytechinus. A cDNA clone was isolated from this screen that represented a 2.1 kb mRNA that did not accumulate during BAPN treatment. Removal of BAPN resulted in the accumulation of this transcript coincident with the onset of gastrulation. This cDNA clone encodes a L. variegatus homologue of LpS1, recently demonstrated to be an ancestral homologue of the aboral ectoderm-specific Spec 1-Spec 2 gene family in S. purpuratus. Nuclear run-on assays in L. pictus suggested that transcriptional activity of LpS1 was selectively inhibited by BAPN treatment. Thus, although the accumulation of many gene products occurred independently of the embryonic collagenous matrix, the accumulation of LpS1 and LvS1 appeared to be mediated by the ECM.


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