scholarly journals Fungal gasdermin-like proteins are controlled by proteolytic cleavage

2021 ◽  
Author(s):  
Corinne Clave ◽  
Witold Dyrka ◽  
Alexandra Granger-Farbos ◽  
Benoit Pinson ◽  
Sven Joachim Saupe ◽  
...  
Keyword(s):  
Cell Death ◽  
Proteolytic Cleavage ◽  
Podospora Anserina ◽  
Cell Death Pathways ◽  
Genomic Landscape ◽  
Dependent Cell ◽  
Pore Forming Proteins ◽  
Mammalian Immune System ◽  
Encoding Genes ◽  
Terminal Effector

Gasdermins are a family of pore-forming proteins controlling an inflammatory cell death reaction in the mammalian immune system. The pore-forming ability of the gasdermin proteins is released by proteolytic cleavage with the removal of their inhibitory C-terminal domain. Recently, gasdermin-like proteins have been discovered in fungi and characterized as cell death-inducing toxins in the context of conspecific non-self discrimination (allorecognition). Although functional analogies have been established between mammalian and fungal gasdermins, the molecular pathways regulating gasdermin activity in fungi remain largely unknown. Here, we characterize a gasdermin-based cell death reaction, controlled by the het-Q allorecognition genes in the filamentous fungus Podospora anserina. We show that the cytotoxic activity of the HET-Q1 gasdermin is controlled by proteolysis. HET-Q1 loses a ~5 kDa C-terminal fragment during the cell death reaction in presence of a subtilisin-like serine protease, termed HET-Q2. Mutational analyses and successful reconstitution of the cell death reaction in a heterologous host (Saccharomyces cerevisiae) suggest that HET-Q2 directly cleaves HET-Q1 to induce cell death. By analysing the genomic landscape of het-Q1 homologs in fungi, we uncovered that the vast majority of the gasdermin genes are clustered with protease-encoding genes. These HET-Q2-like proteins carry either subtilisin-like or caspase-related proteases, which in some cases correspond to the N-terminal effector domain of NOD-like receptor proteins (NLRs). This study thus reveals the proteolytic regulation of gasdermins in fungi and establishes evolutionary parallels between fungal and mammalian gasdermin-dependent cell death pathways.

Mitochondrial dynamics in yeast cell death and aging

2011 ◽  
Vol 39 (5) ◽  
pp. 1520-1526 ◽  
Author(s):  
Ralf J. Braun ◽  
Benedikt Westermann
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Mitochondrial Dynamics ◽  
Progressive Increase ◽  
Mitochondrial Morphology ◽  
Aging Research ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cell Death Pathways ◽  
Dependent Cell ◽  
Mitochondrial Networks

Mitochondria play crucial roles in programmed cell death and aging. Different stimuli activate distinct mitochondrion-dependent cell death pathways, and aging is associated with a progressive increase in mitochondrial damage, culminating in oxidative stress and cellular dysfunction. Mitochondria are highly dynamic organelles that constantly fuse and divide, forming either interconnected mitochondrial networks or separated fragmented mitochondria. These processes are believed to provide a mitochondrial quality control system and enable an effective adaptation of the mitochondrial compartment to the metabolic needs of the cell. The baker's yeast, Saccharomyces cerevisiae, is an established model for programmed cell death and aging research. The present review summarizes how mitochondrial morphology is altered on induction of cell death or on aging and how this correlates with the induction of different cell death pathways in yeast. We highlight the roles of the components of the mitochondrial fusion and fission machinery that affect and regulate cell death and aging.

scholarly journals Combination of IAP antagonist and IFNγ activates novel caspase-10- and RIPK1-dependent cell death pathways

2017 ◽  
Vol 24 (3) ◽  
pp. 481-491 ◽  
Author(s):  
Maria C Tanzer ◽  
Nufail Khan ◽  
James A Rickard ◽  
Nima Etemadi ◽  
Najoua Lalaoui ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Death Pathways ◽  
Iap Antagonist ◽  
Dependent Cell

Caspase-cleaved HPK1 induces CD95L-independent activation-induced cell death in T and B lymphocytes

Blood ◽  
2007 ◽  
Vol 110 (12) ◽  
pp. 3968-3977 ◽  
Author(s):  
Dirk Brenner ◽  
Alexander Golks ◽  
Mareike Becker ◽  
Wolfgang Müller ◽  
Christian R. Frey ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Cell Fate ◽  
B Lymphocytes ◽  
T And B Lymphocytes ◽  
Cell Death Pathways ◽  
Activation Induced Cell Death ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Interfering Rna

Abstract Life and death of peripheral lymphocytes is strictly controlled to maintain physiologic levels of T and B cells. Activation-induced cell death (AICD) is one mechanism to delete superfluous lymphocytes by restimulation of their immunoreceptors and it depends partially on the CD95/CD95L system. Recently, we have shown that hematopoietic progenitor kinase 1 (HPK1) determines T-cell fate. While full-length HPK1 is essential for NF-κB activation in T cells, the C-terminal fragment of HPK1, HPK1-C, suppresses NF-κB and sensitizes toward AICD by a yet undefined cell death pathway. Here we show that upon IL-2–driven expansion of primary T cells, HPK1 is converted to HPK1-C by a caspase-3 activity below the threshold of apoptosis induction. HPK1-C se-lectively blocks induction of NF-κB–dependent antiapoptotic Bcl-2 family members but not of the proapoptotic Bcl-2 family member Bim. Interestingly, T and B lymphocytes from HPK1-C transgenic mice undergo AICD independently of the CD95/CD95L system but involving caspase-9. Knock down of HPK1/HPK1-C or Bim by small interfering RNA shows that CD95L-dependent and HPK1/HPK1-C–dependent cell death pathways complement each other in AICD of primary T cells. Our results define HPK1-C as a suppressor of antiapoptotic Bcl-2 proteins and provide a molecular basis for our understanding of CD95L-independent AICD of lymphocytes.

scholarly journals Partial Prion Cross-Seeding between Fungal and Mammalian Amyloid Signaling Motifs

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thierry Bardin ◽  
Asen Daskalov ◽  
Sophie Barrouilhet ◽  
Alexandra Granger-Farbos ◽  
Bénédicte Salin ◽  
...  
Keyword(s):  
Cell Death ◽  
Filamentous Fungi ◽  
Sequence Similarity ◽  
Podospora Anserina ◽  
Content Type ◽  
Cell Death Pathways ◽  
Prion Propagation ◽  
Signaling Modules ◽  
Β Sheet

ABSTRACT In filamentous fungi, NLR-based signalosomes activate downstream membrane-targeting cell death-inducing proteins by a mechanism of amyloid templating. In the species Podospora anserina, two such signalosomes, NWD2/HET-S and FNT1/HELLF, have been described. An analogous system involving a distinct amyloid signaling motif, termed PP, was also identified in the genome of the species Chaetomium globosum and studied using heterologous expression in Podospora anserina. The PP motif bears resemblance to the RIP homotypic interaction motif (RHIM) and to RHIM-like motifs controlling necroptosis in mammals and innate immunity in flies. We identify here a third NLR signalosome in Podospora anserina comprising a PP motif and organized as a two-gene cluster encoding an NLR and an HELL domain cell death execution protein termed HELLP. We show that the PP motif region of HELLP forms a prion we term [π] and that [π] prions trigger the cell death-inducing activity of full-length HELLP. We detect no prion cross-seeding between HET-S, HELLF, and HELLP amyloid motifs. In addition, we find that, like PP motifs, RHIMs from human RIP1 and RIP3 kinases are able to form prions in Podospora and that [π] and [Rhim] prions partially cross-seed. Our study shows that Podospora anserina displays three independent cell death-inducing amyloid signalosomes. Based on the described functional similarity between RHIM and PP, it appears likely that these amyloid motifs constitute evolutionarily related cell death signaling modules. IMPORTANCE Amyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell death execution proteins through a process of amyloid templating akin to prion propagation. Among these fungal amyloid signaling sequences, the PP motif stands out because it shows similarity to the RHIM, an amyloid sequence controlling necroptotic cell death in mammals. We characterized an amyloid signaling system comprising a PP motif in the model species Podospora anserina, thus bringing to three the number of independent amyloid signaling cell death pathways described in that species. We then showed that human RHIMs not only propagate as prions in P. anserina but also partially cross-seed with fungal PP prions. These results indicate that, in addition to showing sequence similarity, the PP and RHIM motifs are at least partially functionally related, supporting a model of long-term evolutionary conservation of amyloid signaling mechanisms from fungi to mammals.

Follicular expression of a human β-cell leukaemia/lymphoma-2 (Bcl-2) transgene does not decrease atresia or increase ovulation rate in swine

2005 ◽  
Vol 17 (4) ◽  
pp. 457 ◽  
Author(s):  
H. D. Guthrie ◽  
R. J. Wall ◽  
V. G. Pursel ◽  
J. A. Foster-Frey ◽  
D. M. Donovan ◽  
...  
Keyword(s):  
Cell Death ◽  
Ectopic Expression ◽  
Immunohistochemical Analysis ◽  
Polymerase Chain Reaction Analysis ◽  
Ovulation Rate ◽  
Cell Leukaemia ◽  
Α Subunit ◽  
Cell Death Pathways ◽  
Cell Death Pathway ◽  
Dependent Cell

Transgenic (TG) gilts carrying a human Bcl-2 cDNA transgene driven by mouse inhibin-α subunit promoter were produced and evaluated to determine if ectopic expression of Bcl-2 in the ovaries would decrease the frequency of atresia in antral follicles and increase ovulation rate. Immunohistochemical analysis showed that the Bcl-2 transgene protein was expressed in granulosa and theca cells, in 86% of healthy and 54% of atretic follicles analysed in TG prepubertal and Day 50 pregnant gilts combined (n = 24). In contrast, Bcl-2 transgene protein was expressed in only 1.4% of healthy and 0% of atretic follicles in non-TG littermates (n = 13). Real-time reverse transcription–polymerase chain reaction analysis confirmed that human Bcl-2 was expressed in follicles of TG gilts. The atresia rate for the TG and non-TG groups did not differ (P > 0.05) for prepubertal (45 v. 59%) and Day 50 pregnant gilts (53 v. 52%) respectively. The mean ± s.e.m. ovulation rate did not differ (P > 0.5) between TG (15.9 ± 0.8, n = 12) and non-TG (16.4 ± 0.6, n = 7) Day 50 pregnant gilts. The molecular basis of the failure of ectopic Bcl-2 expression to increase the ratio of healthy to atretic follicles is unknown, but it is possible that the activity of the mitochondrial-dependent cell death pathway was not neutralized by ectopic expression of human Bcl-2 or that other cell death pathways compensated for the decreased mitochondrial-dependent cell death.

scholarly journals Partial prion cross-seeding between fungal and mammalian amyloid signaling motifs

2020 ◽  
Author(s):  
Thierry Bardin ◽  
Asen Daskalov ◽  
Sophie Barrouilhet ◽  
Alexandra Granger-Farbos ◽  
Bénédicte Salin ◽  
...  
Keyword(s):  
Cell Death ◽  
Filamentous Fungi ◽  
Sequence Similarity ◽  
Podospora Anserina ◽  
Cell Death Pathways ◽  
Prion Propagation ◽  
Cell Death Signaling ◽  
Signaling Modules ◽  
Β Sheet

AbstractIn filamentous fungi, NLR-based signalosomes activate downstream membrane-targeting cell-death inducing proteins by a mechanism of amyloid templating. In the species Podospora anserina, two such signalosomes, NWD2/HET-S and FNT1/HELLF have been described. An analogous system, involving a distinct amyloid signaling motif termed PP was also identified in the genome of the species Chaetomium globosum and studied using heterologous expression in Podospora anserina. The PP-motif bears resemblance to the RHIM and RHIM-like motifs controlling necroptosis in mammals and innate immunity in flies. We identified here, a third NLR signalosome in Podospora anserina comprising a PP-motif and organized as a two-gene cluster encoding a NLR and a HELL-domain cell-death execution protein termed HELLP. We show that the PP-motif region of HELLP forms a prion we term [π] and that [π] prions trigger the cell-death inducing activity of full length HELLP. We detect no prion cross-seeding between HET-S, HELLF and HELLP amyloid motifs. In addition, we find that akin to PP-motifs, RHIM motifs from human RIP1 and RIP3 kinases are able to form prions in Podospora, and that [π] and [Rhim] prions partially cross-seed. Our study shows that Podospora anserina displays three independent cell-death inducing amyloid signalosomes. Based on the described functional similarity between RHIM and PP, it appears likely that these amyloid motifs constitute evolutionary related cell-death signaling modules.ImportanceAmyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell-death execution proteins through a process of amyloid templating akin to prion propagation.Among these fungal amyloid signaling sequences, the PP-motif stands out because it shows similarity to RHIM, an amyloid sequence controlling necroptotic cell-death in mammals. We characterized an amyloid signaling system comprising a PP-motif in the model species Podospora anserina thus bringing to three the number of independent amyloid signaling cell death pathways described in that species. We then show that human RHIM motifs not only propagate as prions in P. anserina but also partially cross-seed with fungal PP-prions. These results indicate that in addition to show sequence similarity, PP and RHIM-motif are at least partially functionally related, supporting a model of long-term evolutionary conservation of amyloid signaling mechanisms from fungi to mammals.

Resveratrol protects photoreceptors by blocking caspase- and PARP-dependent cell death pathways

2018 ◽  
Vol 129 ◽  
pp. 569-581 ◽  
Author(s):  
Shu-Yan Liu ◽  
Jing-Yao Song ◽  
Bin Fan ◽  
Ying Wang ◽  
Yi-Ran Pan ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Death Pathways ◽  
Dependent Cell

scholarly journals The actin nucleation factors JMY and WHAMM enable a rapid Arp2/3 complex-mediated intrinsic pathway of apoptosis

PLoS Genetics ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. e1009512
Author(s):  
Virginia L. King ◽  
Nathan K. Leclair ◽  
Alyssa M. Coulter ◽  
Kenneth G. Campellone
Keyword(s):  
Cell Death ◽  
Actin Assembly ◽  
Actin Nucleation ◽  
Caspase Cleavage ◽  
Cellular Processes ◽  
Cell Death Pathways ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Family Gene ◽  
Induced Apoptosis

The actin cytoskeleton is a well-known player in most vital cellular processes, but comparably little is understood about how the actin assembly machinery impacts programmed cell death pathways. In the current study, we explored roles for the human Wiskott-Aldrich Syndrome Protein (WASP) family of actin nucleation factors in DNA damage-induced apoptosis. Inactivation of each WASP-family gene revealed that two of them, JMY and WHAMM, are necessary for rapid apoptotic responses. JMY and WHAMM participate in a p53-dependent cell death pathway by enhancing mitochondrial permeabilization, initiator caspase cleavage, and executioner caspase activation. JMY-mediated apoptosis requires actin nucleation via the Arp2/3 complex, and actin filaments are assembled in cytoplasmic territories containing clusters of cytochrome c and active caspase-3. The loss of JMY additionally results in significant changes in gene expression, including upregulation of the WHAMM-interacting G-protein RhoD. Depletion or deletion of RHOD increases cell death, suggesting that RhoD normally contributes to cell survival. These results give rise to a model in which JMY and WHAMM promote intrinsic cell death responses that can be opposed by RhoD.

scholarly journals Lysoptosis is an evolutionarily conserved cell death pathway moderated by intracellular serpins

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Cliff J. Luke ◽  
Stephanie Markovina ◽  
Misty Good ◽  
Ira E. Wight ◽  
Brian J. Thomas ◽  
...  
Keyword(s):  
Cell Death ◽  
Cathepsin L ◽  
Cysteine Protease Inhibitor ◽  
C Elegans ◽  
Cell Death Pathways ◽  
Cell Death Pathway ◽  
Endogenous Inhibitors ◽  
Regulated Cell Death ◽  
Evolutionarily Conserved ◽  
Dependent Cell

AbstractLysosomal membrane permeabilization (LMP) and cathepsin release typifies lysosome-dependent cell death (LDCD). However, LMP occurs in most regulated cell death programs suggesting LDCD is not an independent cell death pathway, but is conscripted to facilitate the final cellular demise by other cell death routines. Previously, we demonstrated that Caenorhabditis elegans (C. elegans) null for a cysteine protease inhibitor, srp-6, undergo a specific LDCD pathway characterized by LMP and cathepsin-dependent cytoplasmic proteolysis. We designated this cell death routine, lysoptosis, to distinguish it from other pathways employing LMP. In this study, mouse and human epithelial cells lacking srp-6 homologues, mSerpinb3a and SERPINB3, respectively, demonstrated a lysoptosis phenotype distinct from other cell death pathways. Like in C. elegans, this pathway depended on LMP and released cathepsins, predominantly cathepsin L. These studies suggested that lysoptosis is an evolutionarily-conserved eukaryotic LDCD that predominates in the absence of neutralizing endogenous inhibitors.

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