scholarly journals A redox-regulated type III metacaspase controls cell death in a marine diatom

2018 ◽  
Author(s):  
Shiri Graff van Creveld ◽  
Shifra Ben-Dor ◽  
Avia Mizrachi ◽  
Uria Alcolombri ◽  
Amanda Hopes ◽  
...  
Keyword(s):  
Cell Death ◽  
Large Scale ◽  
Redox Regulation ◽  
Marine Phytoplankton ◽  
Marine Diatom ◽  
Type Iii ◽  
Calcium Dependent ◽  
A Cell ◽  
Regulate Cell Death

Programmed cell death (PCD) in marine phytoplankton was suggested as one of the mechanisms that facilitates large scale bloom demise. Yet, the molecular basis for algal PCD machinery is rudimentary. Metacaspases are considered ancestral proteases that regulate cell death, but their activity and role in algae are still elusive. Here we biochemically characterized a recombinant metacaspase 5 from the model diatom Phaeodactylum tricornutum (PtMC5), revealing calcium-dependent protease activity. This activity includes auto-processing and cleavage following arginine. PtMC5 overexpressing cells exhibited higher metacaspase activity and were more sensitive to a diatom-specific infochemical compared to WT cells. Mutagenesis of potential disulfide-forming cysteines decreased PtMC5 activity, suggesting redox regulation. This cysteine pair is widespread in diatom type III metacaspases, but was not found in any other taxa. The characterization of a cell death associated protein in marine phytoplankton will enable deeper understanding of the ecological significance of PCD in bloom dynamics.

scholarly journals Biochemical Characterization of a Novel Redox-Regulated Metacaspase in a Marine Diatom

2021 ◽  
Vol 12 ◽  
Author(s):  
Shiri Graff van Creveld ◽  
Shifra Ben-Dor ◽  
Avia Mizrachi ◽  
Uria Alcolombri ◽  
Amanda Hopes ◽  
...  
Keyword(s):  
Cell Death ◽  
Biochemical Characterization ◽  
Site Directed Mutagenesis ◽  
Marine Diatom ◽  
Type Iii ◽  
Calcium Dependent ◽  
Evolutionary Origins ◽  
Cell Extracts ◽  
A Cell

Programmed cell death (PCD) in marine microalgae was suggested to be one of the mechanisms that facilitates bloom demise, yet its molecular components in phytoplankton are unknown. Phytoplankton are completely lacking any of the canonical components of PCD, such as caspases, but possess metacaspases. Metacaspases were shown to regulate PCD in plants and some protists, but their roles in algae and other organisms are still elusive. Here, we identified and biochemically characterized a type III metacaspase from the model diatom Phaeodactylum tricornutum, termed PtMCA-IIIc. Through expression of recombinant PtMCA-IIIc in E. coli, we revealed that PtMCA-IIIc exhibits a calcium-dependent protease activity, including auto-processing and cleavage after arginine. Similar metacaspase activity was detected in P. tricornutum cell extracts. PtMCA-IIIc overexpressing cells exhibited higher metacaspase activity, while CRISPR/Cas9-mediated knockout cells had decreased metacaspase activity compared to WT cells. Site-directed mutagenesis of cysteines that were predicted to form a disulfide bond decreased recombinant PtMCA-IIIc activity, suggesting its enhancement under oxidizing conditions. One of those cysteines was oxidized, detected in redox proteomics, specifically in response to lethal concentrations of hydrogen peroxide and a diatom derived aldehyde. Phylogenetic analysis revealed that this cysteine-pair is unique and widespread among diatom type III metacaspases. The characterization of a cell death associated protein in diatoms provides insights into the evolutionary origins of PCD and its ecological significance in algal bloom dynamics.

scholarly journals Identification and characterization of GRIM-1, a cell-death-associated gene product

2010 ◽  
Vol 123 (16) ◽  
pp. 2781-2791 ◽  
Author(s):  
E. R. Hofmann ◽  
S. C. Nallar ◽  
L. Lin ◽  
J. D'Cunha ◽  
D. J. Lindner ◽  
...  
Keyword(s):  
Cell Death ◽  
Gene Product ◽  
A Cell ◽  
Identification And Characterization

Characterization of Bax-ς, a Cell Death-Inducing Isoform of Bax

2000 ◽  
Vol 270 (3) ◽  
pp. 868-879 ◽  
Author(s):  
Estelle Schmitt ◽  
Claudie Paquet ◽  
Myriam Beauchemin ◽  
Jessica Dever-Bertrand ◽  
Richard Bertrand
Keyword(s):  
Cell Death ◽  
A Cell

scholarly journals MORPHOLOGICAL AND BIOCHEMICAL CHARACTERIZATION OF A CELL DEATH PROCESS INDUCED BY E3, A NEW SYNTHETIC DIARYLSULFONILUREA ANALOGUE

2001 ◽  
Vol 1 (S3) ◽  
pp. 50-50
Author(s):  
M. Alonso ◽  
M. Miglaccio ◽  
I. Encio ◽  
A. Asumendi ◽  
V. Martinez-Merino ◽  
...  
Keyword(s):  
Cell Death ◽  
Biochemical Characterization ◽  
Death Process ◽  
Cell Death Process ◽  
A Cell

scholarly journals Identification of Nicotiana benthamiana Genes Involved in Pathogen-Associated Molecular Pattern–Triggered Immunity

2010 ◽  
Vol 23 (6) ◽  
pp. 715-726 ◽  
Author(s):  
Suma Chakravarthy ◽  
André C. Velásquez ◽  
Sophia K. Ekengren ◽  
Alan Collmer ◽  
Gregory B. Martin
Keyword(s):  
Cell Death ◽  
Nicotiana Benthamiana ◽  
Large Scale ◽  
Forward Genetics ◽  
Hormone Signaling ◽  
Virus Induced Gene Silencing ◽  
Molecular Pattern ◽  
Cell Death Response ◽  
A Cell ◽  
Pathogen Associated Molecular Pattern

In order to identify components of pathogen-associated molecular pattern–triggered immunity (PTI) pathways in Nicotiana benthamiana, we conducted a large-scale forward-genetics screen using virus-induced gene silencing and a cell-death-based assay for assessing PTI. The assay relied on four combinations of PTI-inducing nonpathogens and cell-death-causing challenger pathogens and was first validated in plants silenced for FLS2 or BAK1. Over 3,200 genes were screened and 14 genes were identified that, when silenced, compromised PTI as judged by the cell-death-based assay. Further analysis indicated that the 14 genes were not involved in a general cell death response. A subset of the genes was found to act downstream of FLS2-mediated PTI induction, and silencing of three genes compromised production of reactive oxygen species in leaves exposed to flg22. The 14 genes encode proteins with potential functions in defense and hormone signaling, protein stability and degradation, energy and secondary metabolism, and cell wall biosynthesis and provide a new resource to explore the molecular basis for the involvement of these processes in PTI.

scholarly journals Creation and characterization of a cell-death reporter cell line for hepatitis C virus infection

2010 ◽  
Vol 86 (2) ◽  
pp. 220-223 ◽  
Author(s):  
Zhilei Chen ◽  
Rudo L. Simeon ◽  
Karuppiah Chockalingam ◽  
Charles M. Rice
Keyword(s):  
Cell Death ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Infection ◽  
Cell Line ◽  
Reporter Cell Line ◽  
Hepatitis C Virus Infection ◽  
Reporter Cell ◽  
A Cell

scholarly journals Retraction: Identification and characterization of GRIM-1, a cell-death-associated gene product

2021 ◽  
Vol 134 (22) ◽  
Author(s):  
Edward R. Hofmann ◽  
Shreeram C. Nallar ◽  
Limei Lin ◽  
Jonathan D'Cunha ◽  
Daniel J. Lindner ◽  
...  
Keyword(s):  
Cell Death ◽  
Gene Product ◽  
A Cell ◽  
Identification And Characterization

scholarly journals Monoacylglycerides from the Diatom Skeletonema marinoi Induce Selective Cell Death in Cancer Cells

Marine Drugs ◽  
2019 ◽  
Vol 17 (11) ◽  
pp. 625 ◽  
Author(s):  
Marco Miceli ◽  
Adele Cutignano ◽  
Mariarosaria Conte ◽  
Raffaella Ummarino ◽  
Alessandra Romanelli ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Line ◽  
Cancer Cell ◽  
Large Scale ◽  
Cancer Cell Line ◽  
Marine Diatom ◽  
Scale Production ◽  
Natural Form ◽  
Hct 116 ◽  
Skeletonema Marinoi

Microalgae are an excellent source of valuable compounds for nutraceutical and cosmeceutical applications. These photosynthesizing microorganisms are amenable for large-scale production, thus overcoming the bottleneck of biomass supply for chemical and activity characterization of bioactive compounds. This characteristic has recently also prompted the screening of microalgae for potential pharmaceutical applications. Here, we show that monoacylglycerides (MAGs) purified from the marine diatom Skeletonema marinoi have selective cytotoxic activity against the haematological cancer cell line U-937 and colon cancer cell line HCT-116 compared to normal MePR-2B cells. LC-MS analysis of the raw extract revealed that in their natural form, MAGs occur as 2-monoacyl derivatives and include mainly C16 and C20 analogues, but they are converted into the corresponding 1-isomers during purification processes. Pure compounds along with the synthetic 1-monoarachidonoylglycerol tested on HCT-116 and U-937 tumor cell lines induced cell death via apoptosis. The mechanism of action was investigated, and we show that it involves the induction of apoptosis through caspase 3/7 activation. These findings pave the way for the possible use of these molecules as potential anticancer agents or as precursors for the generation of new and more potent and selective compounds against tumor cells.

Characterization of a cell death‐inducing endonuclease‐like venom protein from the parasitoid wasp Pteromalus puparum ( Hymenoptera: Pteromalidae )

2020 ◽  
Vol 77 (1) ◽  
pp. 224-233
Author(s):  
Jiale Wang ◽  
Zhichao Yan ◽  
Shan Xiao ◽  
Beibei Wang ◽  
Qi Fang ◽  
...  
Keyword(s):  
Cell Death ◽  
Parasitoid Wasp ◽  
Venom Protein ◽  
Pteromalus Puparum ◽  
A Cell
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