scholarly journals PaTrx1 and PaTrx3, Two Cytosolic Thioredoxins of the Filamentous Ascomycete Podospora anserina Involved in Sexual Development and Cell Degeneration

2007 ◽  
Vol 6 (12) ◽  
pp. 2323-2331 ◽  
Author(s):  
Fabienne Malagnac ◽  
Benjamin Klapholz ◽  
Philippe Silar

ABSTRACT In various organisms, thioredoxins are known to be involved in the reduction of protein disulfide bonds and in protecting the cell from oxidative stress. Genes encoding thioredoxins were found by searching the complete genome sequence of the filamentous ascomycete Podospora anserina. Among them, PaTrx1, PaTrx2, and PaTrx3 are predicted to be canonical cytosolic proteins without additional domains. Targeted disruption of PaTrx1, PaTrx2, and PaTrx3 shows that PaTrx1 is the major thioredoxin involved in sulfur metabolism. Deletions have no effect on peroxide resistance; however, data show that either PaTrx1 or PaTrx3 is necessary for sexual reproduction and for the development of the crippled growth cell degeneration (CG), processes that also required the PaMpk1 mitogen-activated protein kinase (MAPK) pathway. Since PaTrx1 PaTrx3 mutants show not an enhancement but rather an impairment in CG, it seems unlikely that PaTrx1 and PaTrx3 thioredoxins participate in the inhibition of this MAPK pathway. Altogether, these results underscore a role for thioredoxins in fungal development.

2021 ◽  
Author(s):  
Aditi Prabhakar ◽  
Beatriz Gonzalez ◽  
Heather Dionne ◽  
Sukanya Basu ◽  
Paul J. Cullen

Mitogen-Activated Protein Kinase (MAPK) pathways control cell differentiation and the response to stress. In Saccharomyces cerevisiae, the MAPK pathway that controls filamentous growth (fMAPK) shares components with the pathway that regulates the response to osmotic stress (HOG). Here, we show that the two pathways exhibit different patterns of activity throughout the cell cycle. The different patterns resulted from different expression profiles of genes encoding mucin sensors that regulate the pathways. Cross-pathway regulation from the fMAPK pathway stimulated the HOG pathway, presumably to modulate fMAPK pathway activity. We also show that the shared tetraspan protein, Sho1p, which has a dynamic localization pattern, induced the fMAPK pathway at the mother-bud neck. A Sho1p-interacting protein, Hof1p, which also localizes to the mother-bud neck and regulates cytokinesis, also regulated the fMAPK pathway. Therefore, spatial and temporal regulation of pathway sensors, and cross-pathway regulation, control a MAPK pathway that regulates cell differentiation in yeast.


Author(s):  
Н.В. Журкова ◽  
Л.А. Гандаева ◽  
А.А. Пушков ◽  
Е.Н. Басаргина ◽  
А.В. Пахомов ◽  
...  

RAS-патии - группа наследственных заболеваний, возникающая вследствие нарушения регуляции функции RAS/MAPK внутриклеточных путей (Ras/mitogen-activated protein kinase). Суммарная частота заболеваний данной группы - 1 случай на 1000 новорожденных. Наиболее часто среди RAS-патий встречается синдром Нунан. В настоящее время описано 13 генов, мутации которых отвечают за развитие данного заболевания, включая ген SHOC2, ассоциированный с Нунан-подобным синдромом и измененной структурой волос (Noonan-like syndrome with loose anagen hair) и ген LZTR1, мутации в котором приводят к развитию синдрома Нунан, тип 2 с аутосомно-рецессивным типом наследования. RASopathies - group of inherited diseases, caused by mutations in genes, encoding components or regulators of the Ras/mitogen-activated protein kinase (MAPK) pathway. We identified 28 patients with inherited diseases from RASopathies: 61% - with Noonan syndrome, 14 % - with Cardiofaciocutaneous syndrome, 14% - with Costello syndrome - 11% - Noonan syndrome-like with loose anagen hair. Mutation c.770C>T, p.S257L in RAF1gene is most common in hypertrophic cardiomyopathy patients with Noonan syndrome. All patients with Noonan syndrome-like with loose anagen hair have mutation c.4A>G , p.S2G in SHOC2 gene.


2021 ◽  
Author(s):  
Melinda Moseley-Alldredge ◽  
Seema Sheoran ◽  
Hayoung Yoo ◽  
Calvin O’Keefe ◽  
Janet E. Richmond ◽  
...  

AbstractL1CAMs are immunoglobulin cell adhesion molecules that play important roles in the development and function of the nervous system. In addition to being associated with autism and schizophrenia spectrum disorders, impaired L1CAM function also underlies the X-linked L1 syndrome, which encompasses a group of neurological conditions, including spastic paraplegia and congenital hydrocephalus. Previous studies on both vertebrate and invertebrate L1CAMs established conserved roles that include axon guidance, dendrite morphogenesis, synapse development, and maintenance of neural architecture. We previously identified a genetic interaction between the C. elegans L1CAM encoded by the sax-7 gene and RAB-3, a GTPase that functions in synaptic neurotransmission; rab-3; sax-7 animals exhibit synthetic locomotion abnormalities and neuronal dysfunction. In this study, we examine the significance of this genetic interaction and show that this synergism also occurs when loss of SAX-7 is combined with mutants of other genes encoding key players of the synaptic vesicle cycle. In contrast, sax-7 does not interact with genes that function in synaptogenesis. These findings suggest a post-developmental role for sax-7 in the regulation of synaptic activity. To further assess this possibility, we conducted electrophysiological recordings and ultrastructural analyses at neuromuscular junctions. Lastly, we performed a forward genetic screen for suppressors of the rab-3; sax-7 synthetic phenotypes, uncovering a role for the Mitogen-activated Protein Kinase (MAPK) pathway in promoting coordinated locomotion.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Qingxue Xu ◽  
Bo Zhao ◽  
Yingze Ye ◽  
Yina Li ◽  
Yonggang Zhang ◽  
...  

AbstractThe nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome is a member of the NLR family of inherent immune cell sensors. The NLRP3 inflammasome can detect tissue damage and pathogen invasion through innate immune cell sensor components commonly known as pattern recognition receptors (PRRs). PRRs promote activation of nuclear factor kappa B (NF-κB) pathways and the mitogen-activated protein kinase (MAPK) pathway, thus increasing the transcription of genes encoding proteins related to the NLRP3 inflammasome. The NLRP3 inflammasome is a complex with multiple components, including an NAIP, CIITA, HET-E, and TP1 (NACHT) domain; apoptosis-associated speck-like protein containing a CARD (ASC); and a leucine-rich repeat (LRR) domain. After ischemic stroke, the NLRP3 inflammasome can produce numerous proinflammatory cytokines, mediating nerve cell dysfunction and brain edema and ultimately leading to nerve cell death once activated. Ischemic stroke is a disease with high rates of mortality and disability worldwide and is being observed in increasingly younger populations. To date, there are no clearly effective therapeutic strategies for the clinical treatment of ischemic stroke. Understanding the NLRP3 inflammasome may provide novel ideas and approaches because targeting of upstream and downstream molecules in the NLRP3 pathway shows promise for ischemic stroke therapy. In this manuscript, we summarize the existing evidence regarding the composition and activation of the NLRP3 inflammasome, the molecules involved in inflammatory pathways, and corresponding drugs or molecules that exert effects after cerebral ischemia. This evidence may provide possible targets or new strategies for ischemic stroke therapy.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1082
Author(s):  
Amandeep Singh ◽  
Jeehoon Ham ◽  
Joseph William Po ◽  
Navin Niles ◽  
Tara Roberts ◽  
...  

Thyroid cancer is the most prevalent endocrine malignancy that comprises mostly indolent differentiated cancers (DTCs) and less frequently aggressive poorly differentiated (PDTC) or anaplastic cancers (ATCs) with high mortality. Utilisation of next-generation sequencing (NGS) and advanced sequencing data analysis can aid in understanding the multi-step progression model in the development of thyroid cancers and their metastatic potential at a molecular level, promoting a targeted approach to further research and development of targeted treatment options including immunotherapy, especially for the aggressive variants. Tumour initiation and progression in thyroid cancer occurs through constitutional activation of the mitogen-activated protein kinase (MAPK) pathway through mutations in BRAF, RAS, mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway and/or receptor tyrosine kinase fusions/translocations, and other genetic aberrations acquired in a stepwise manner. This review provides a summary of the recent genetic aberrations implicated in the development and progression of thyroid cancer and implications for immunotherapy.


2021 ◽  
Vol 22 (6) ◽  
pp. 2952
Author(s):  
Tzu-Yu Hou ◽  
Shi-Bei Wu ◽  
Hui-Chuan Kau ◽  
Chieh-Chih Tsai

Transforming growth factor-β1 (TGF-β1)-induced myofibroblast transdifferentiation from orbital fibroblasts is known to dominate tissue remodeling and fibrosis in Graves’ ophthalmopathy (GO). However, the signaling pathways through which TGF-β1 activates Graves’ orbital fibroblasts remain unclear. This study investigated the role of the mitogen-activated protein kinase (MAPK) pathway in TGF-β1-induced myofibroblast transdifferentiation in human Graves’ orbital fibroblasts. The MAPK pathway was assessed by measuring the phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular-signal-regulated kinase (ERK) by Western blots. The expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and fibronectin representing fibrogenesis was estimated. The activities of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) responsible for extracellular matrix (ECM) metabolism were analyzed. Specific pharmacologic kinase inhibitors were used to confirm the involvement of the MAPK pathway. After treatment with TGF-β1, the phosphorylation levels of p38 and JNK, but not ERK, were increased. CTGF, α-SMA, and fibronectin, as well as TIMP-1 and TIMP-3, were upregulated, whereas the activities of MMP-2/-9 were inhibited. The effects of TGF-β1 on the expression of these factors were eliminated by p38 and JNK inhibitors. The results suggested that TGF-β1 could induce myofibroblast transdifferentiation in human Graves’ orbital fibroblasts through the p38 and JNK pathways.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3476
Author(s):  
Kwang-Woo Jung ◽  
Moon-Soo Chung ◽  
Hyoung-Woo Bai ◽  
Byung Yeoup Chung ◽  
Sungbeom Lee

Due to lifespan extension and changes in global climate, the increase in mycoses caused by primary and opportunistic fungal pathogens is now a global concern. Despite increasing attention, limited options are available for the treatment of systematic and invasive mycoses, owing to the evolutionary similarity between humans and fungi. Although plants produce a diversity of chemicals to protect themselves from pathogens, the molecular targets and modes of action of these plant-derived chemicals have not been well characterized. Using a reverse genetics approach, the present study revealed that thymol, a monoterpene alcohol from Thymus vulgaris L., (Lamiaceae), exhibits antifungal activity against Cryptococcus neoformans by regulating multiple signaling pathways including calcineurin, unfolded protein response, and HOG (high-osmolarity glycerol) MAPK (mitogen-activated protein kinase) pathways. Thymol treatment reduced the intracellular concentration of Ca2+ by controlling the expression levels of calcium transporter genes in a calcineurin-dependent manner. We demonstrated that thymol decreased N-glycosylation by regulating the expression levels of genes involved in glycan-mediated post-translational modifications. Furthermore, thymol treatment reduced endogenous ergosterol content by decreasing the expression of ergosterol biosynthesis genes in a HOG MAPK pathway-dependent manner. Collectively, this study sheds light on the antifungal mechanisms of thymol against C. neoformans.


Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1763-1775 ◽  
Author(s):  
Bénédicte Gagny ◽  
Philippe Silar

Abstract In an attempt to decipher their role in the life history and senescence process of the filamentous fungus Podospora anserina, we have cloned the su1 and su2 genes, previously identified as implicated in cytosolic translation fidelity. We show that these genes are the equivalents of the SUP35 and SUP45 genes of Saccharomyces cerevisiae, which encode the cytosolic translation termination factors eRF3 and eRF1, respectively. Mutations in these genes that suppress nonsense mutations may lead to drastic mycelium morphology changes and sexual impairment but have little effect on life span. Deletion of su1, coding for the P. anserina eRF3, is lethal. Diminution of its expression leads to a nonsense suppressor phenotype whereas its overexpression leads to an antisuppressor phenotype. P. anserina eRF3 presents an N-terminal region structurally related to the yeast eRF3 one. Deletion of the N-terminal region of P. anserina eRF3 does not cause any vegetative alteration; especially life span is not changed. However, it promotes a reproductive impairment. Contrary to what happens in S. cerevisiae, deletion of the N terminus of the protein promotes a nonsense suppressor phenotype. Genetic analysis suggests that this domain of eRF3 acts in P. anserina as a cis-activator of the C-terminal portion and is required for proper reproduction.


Genetics ◽  
1995 ◽  
Vol 141 (4) ◽  
pp. 1275-1285 ◽  
Author(s):  
K N Huang ◽  
L S Symington

Abstract The PKC1 gene product, protein kinase C, regulates a mitogen-activated protein kinase (MAPK) cascade, which is implicated in cell wall metabolism. Previously, we identified the pkc1-4 allele in a screen for mutants with increased rates of recombination, indicating that PKC1 may also regulate DNA metabolism. The pkc1-4 allele also conferred a temperature-sensitive (ts) growth defect. Extragenic suppressors were isolated that suppress both the ts and hyperrecombination phenotypes conferred by the pkc1-4 mutation. Eight of these suppressors for into two complementation groups, designated KCS1 and KCS2. KCS1 was cloned and found to encode a novel protein with homology to the basic leucine zipper family of transcription factors. KCS2 is allelic with PTC1, a previously identified type 2C serine/threonine protein phosphatase. Although mutation of either KCS1 or PTC1 causes little apparent phenotype, the kcs1 delta ptc1 delta double mutant fails to grow at 30 degrees. Furthermore, the ptc1 deletion mutation is synthetically lethal in combination with a mutation in MPK1, which encodes a MAPK homologue proposed to act in the PKC1 pathway. Because PTC1 was initially isolated as a component of the Hog1p MAPK pathway, it appears that these two MAPK cascades share a common regulatory feature.


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