scholarly journals Recombinant Expression, Biophysical Characterization, and Cardiolipin-Induced Changes of Two Caenorhabditis elegans Cytochrome c Proteins

Biochemistry ◽  
2013 ◽  
Vol 52 (4) ◽  
pp. 653-666 ◽  
Author(s):  
Amber J. Vincelli ◽  
Danielle S. Pottinger ◽  
Fangfang Zhong ◽  
Jonas Hanske ◽  
Stéphane G. Rolland ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Cytochrome C ◽  
Recombinant Expression ◽  
Biophysical Characterization ◽  
C Proteins ◽  
Induced Changes

scholarly journals Biophysical characterization of the SARS-CoV-2 E protein

2021 ◽  
Author(s):  
Aujan Mehregan ◽  
Sergio Perez-Conesa ◽  
Yuxuan Zhuang ◽  
Ahmad Elbahnsi ◽  
Diletta Pasini ◽  
...  
Keyword(s):  
Recombinant Expression ◽  
Structural Data ◽  
Md Simulations ◽  
Full Length ◽  
Coarse Grained ◽  
Biophysical Characterization ◽  
Viral Budding ◽  
Nmr Structures ◽  
E Protein

SARS-CoV-2 is the virus responsible for the COVID-19 pandemic which continues to wreak havoc across the world, over a year and a half after its effects were first reported in the general media. Current fundamental research efforts largely focus on the SARS-CoV-2 Spike protein. Since successful antiviral therapies are likely to target multiple viral components, there is considerable interest in understanding the biophysical role of its other proteins, in particular structural membrane proteins. Here, we have focused our efforts on the characterization of the full-length E protein from SARS-CoV-2, combining experimental and computational approaches. Recombinant expression of the full-length E protein from SARS-CoV-2 reveals that this membrane protein is capable of independent multimerization, possibly as a tetrameric or smaller species. Fluorescence microscopy shows that the protein localizes intracellularly, and coarse-grained MD simulations indicate it causes bending of the surrounding lipid bilayer, corroborating a potential role for the E protein in viral budding. Although we did not find robust electrophysiological evidence of ion-channel activity, cells transfected with the E protein exhibited reduced intracellular Ca2+, which may further promote viral replication. However, our atomistic MD simulations revealed that previous NMR structures are relatively unstable, and result in models incapable of ion conduction. Our study highlights the importance of using high-resolution structural data obtained from a full-length protein to gain detailed molecular insights, and eventually permitting virtual drug screening.

scholarly journals The two cytochrome c species, DC3 and DC4, are not required for caspase activation and apoptosis in Drosophila cells

2004 ◽  
Vol 167 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Loretta Dorstyn ◽  
Kathryn Mills ◽  
Yuri Lazebnik ◽  
Sharad Kumar
Keyword(s):  
Cytochrome C ◽  
Ectopic Expression ◽  
Human Cells ◽  
Loss Of Function ◽  
Caspase Activation ◽  
Drosophila Cell ◽  
Drosophila Development ◽  
Cell Lysates ◽  
C Proteins ◽  
Drosophila Cells

In Drosophila, activation of the apical caspase DRONC requires the apoptotic protease-activating factor homologue, DARK. However, unlike caspase activation in mammals, DRONC activation is not accompanied by the release of cytochrome c from mitochondria. Drosophila encodes two cytochrome c proteins, Cytc-p (DC4) the predominantly expressed species, and Cytc-d (DC3), which is implicated in caspase activation during spermatogenesis. Here, we report that silencing expression of either or both DC3 and DC4 had no effect on apoptosis or activation of DRONC and DRICE in Drosophila cells. We find that loss of function mutations in dc3 and dc4, do not affect caspase activation during Drosophila development and that ectopic expression of DC3 or DC4 in Drosophila cells does not induce caspase activation. In cell-free studies, recombinant DC3 or DC4 failed to activate caspases in Drosophila cell lysates, but remarkably induced caspase activation in extracts from human cells. Overall, our results argue that DARK-mediated DRONC activation occurs independently of cytochrome c.

scholarly journals Recombinant expression, purification, and biophysical characterization of the transmembrane and membrane proximal domains of HIV-1 gp41

2014 ◽  
Vol 23 (11) ◽  
pp. 1607-1618 ◽  
Author(s):  
Zhen Gong ◽  
Sarah A. Kessans ◽  
Lusheng Song ◽  
Katerina Dörner ◽  
Ho-Hsien Lee ◽  
...  
Keyword(s):  
Recombinant Expression ◽  
Biophysical Characterization ◽  
Hiv 1

Magnetochrome: a c-type cytochrome domain specific to magnetotatic bacteria

2012 ◽  
Vol 40 (6) ◽  
pp. 1319-1323 ◽  
Author(s):  
Marina I. Siponen ◽  
Géraldine Adryanczyk ◽  
Nicolas Ginet ◽  
Pascal Arnoux ◽  
David Pignol
Keyword(s):  
Cytochrome C ◽  
Iron Acquisition ◽  
Magnetic Domain ◽  
Redox Potentials ◽  
Protein Sequence Analysis ◽  
Biophysical Characterization ◽  
Domain Specific ◽  
New Family ◽  
Periplasmic Proteins ◽  
Field Lines

Magnetotactic bacteria consist of a group of taxonomically, physiologically and morphologically diverse prokaryotes, with the singular ability to align with geomagnetic field lines, a phenomenon referred to as magnetotaxis. This magnetotactic property is due to the presence of iron-rich crystals embedded in lipidic vesicles forming an organelle called the magnetosome. Magnetosomes are composed of single-magnetic-domain nanocrystals of magnetite (Fe3O4) or greigite (Fe3S4) embedded in biological membranes, thereby forming a prokaryotic organelle. Four specific steps are described in this organelle formation: (i) membrane specialization, (ii) iron acquisition, (iii) magnetite (or greigite) biocrystallization, and (iv) magnetosome alignment. The formation of these magnetic crystals is a genetically controlled process, which is governed by enzyme-catalysed processes. On the basis of protein sequence analysis of genes known to be involved in magnetosome formation in Magnetospirillum magneticum AMB-1, we have identified a subset of three membrane-associated or periplasmic proteins containing a double cytochrome c signature motif CXXCH: MamE, MamP and MamT. The presence of these proteins suggests the existence of an electron-transport chain inside the magnetosome, contributing to the process of biocrystallization. We have performed heterologous expression in E. coli of the cytochrome c motif-containing domains of MamE, MamP and MamT. Initial biophysical characterization has confirmed that MamE, MamP and MamT are indeed c-type cytochromes. Furthermore, determination of redox potentials for this new family of c-type cytochromes reveals midpoint potentials of −76 and −32 mV for MamP and MamE respectively.

scholarly journals The Mitochondrial Na+/Ca2+ Exchanger Inhibitor CGP37157 Preserves Muscle Structure and Function to Increase Lifespan and Healthspan in Caenorhabditis elegans

2021 ◽  
Vol 12 ◽  
Author(s):  
Paloma García-Casas ◽  
Pilar Alvarez-Illera ◽  
Eva Gómez-Orte ◽  
Juan Cabello ◽  
Rosalba I. Fonteriz ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Regular Structure ◽  
Fold Increase ◽  
Maximum Speed ◽  
Tor Pathway ◽  
C Elegans ◽  
Promising Target ◽  
Metabolism Enzymes ◽  
And Function ◽  
Induced Changes

We have reported recently that the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157 extends lifespan in Caenorhabditis elegans by a mechanism involving mitochondria, the TOR pathway and the insulin/IGF1 pathway. Here we show that CGP37157 significantly improved the evolution with age of the sarcomeric regular structure, delaying development of sarcopenia in C. elegans body wall muscle and increasing the average and maximum speed of the worms. Similarly, CGP37157 favored the maintenance of a regular mitochondrial structure during aging. We have also investigated further the mechanism of the effect of CGP37157 by studying its effect in mutants of aak-1;aak-2/AMP-activated kinase, sir-2.1/sirtuin, rsks-1/S6 kinase and daf-16/FOXO. We found that this compound was still effective increasing lifespan in all these mutants, indicating that these pathways are not involved in the effect. We have then monitored pharynx cytosolic and mitochondrial Ca2+ signalling and our results suggest that CGP37157 is probably inhibiting not only the mitochondrial Na+/Ca2+ exchanger, but also Ca2+ entry through the plasma membrane. Finally, a transcriptomic study detected that CGP37157 induced changes in lipid metabolism enzymes and a four-fold increase in the expression of ncx-6, one of the C. elegans mitochondrial Na+/Ca2+ exchangers. In summary, CGP37157 increases both lifespan and healthspan by a mechanism involving changes in cytosolic and mitochondrial Ca2+ homeostasis. Thus, Ca2+ signalling could be a promising target to act on aging.

Predictions of structural homologies in cytochrome c proteins

1971 ◽  
Vol 144 (2) ◽  
pp. 576-583 ◽  
Author(s):  
Peter N. Lewis ◽  
Harold A. Scheraga
Keyword(s):  
Cytochrome C ◽  
C Proteins
Sign in / Sign up

Export Citation Format

Share Document