Welcome to the incredible world of MAP Kinases

AbstractThere is increasing evidence that some functionally related, co-expressed genes cluster within eukaryotic genomes. We present a novel pipeline that delineates such eukaryotic gene clusters. Using this tool for bread wheat, we uncovered 44 clusters of genes that are responsive to the fungal pathogen Fusarium graminearum. As expected, these Fusarium-responsive gene clusters (FRGCs) included metabolic gene clusters, many of which are associated with disease resistance, but hitherto not described for wheat. However, the majority of the FRGCs are non-metabolic, many of which contain clusters of paralogues, including those implicated in plant disease responses, such as glutathione transferases, MAP kinases, and germin-like proteins. 20 of the FRGCs encode nonhomologous, non-metabolic genes (including defence-related genes). One of these clusters includes the characterised Fusarium resistance orphan gene, TaFROG. Eight of the FRGCs map within 6 FHB resistance loci. One small QTL on chromosome 7D (4.7 Mb) encodes eight Fusarium-responsive genes, five of which are within a FRGC. This study provides a new tool to identify genomic regions enriched in genes responsive to specific traits of interest and applied herein it highlighted gene families, genetic loci and biological pathways of importance in the response of wheat to disease.

Download Full-text

Stress-Activated Protein Kinase Signalling Regulates Mycoparasitic Hyphal-Hyphal Interactions in Trichoderma atroviride

Journal of Fungi ◽

10.3390/jof7050365 ◽

2021 ◽

Vol 7 (5) ◽

pp. 365

Author(s):

Dubraska Moreno-Ruiz ◽

Linda Salzmann ◽

Mark D. Fricker ◽

Susanne Zeilinger ◽

Alexander Lichius

Keyword(s):

Protein Kinase ◽

Map Kinases ◽

Plant Pathogens ◽

Tip Growth ◽

Mitogen Activated Protein Kinase ◽

Trichoderma Atroviride ◽

Contact Phase ◽

Fungal Plant Pathogens ◽

Signalling Network ◽

Mapk Signalling

Trichoderma atroviride is a mycoparasitic fungus used as biological control agent against fungal plant pathogens. The recognition and appropriate morphogenetic responses to prey-derived signals are essential for successful mycoparasitism. We established microcolony confrontation assays using T. atroviride strains expressing cell division cycle 42 (Cdc42) and Ras-related C3 botulinum toxin substrate 1 (Rac1) interactive binding (CRIB) reporters to analyse morphogenetic changes and the dynamic displacement of localized GTPase activity during polarized tip growth. Microscopic analyses showed that Trichoderma experiences significant polarity stress when approaching its fungal preys. The perception of prey-derived signals is integrated via the guanosine triphosphatase (GTPase) and mitogen-activated protein kinase (MAPK) signalling network, and deletion of the MAP kinases Trichoderma MAPK 1 (Tmk1) and Tmk3 affected T. atroviride tip polarization, chemotropic growth, and contact-induced morphogenesis so severely that the establishment of mycoparasitism was highly inefficient to impossible. The responses varied depending on the prey species and the interaction stage, reflecting the high selectivity of the signalling process. Our data suggest that Tmk3 affects the polarity-stress adaptation process especially during the pre-contact phase, whereas Tmk1 regulates contact-induced morphogenesis at the early-contact phase. Neither Tmk1 nor Tmk3 loss-of-function could be fully compensated within the GTPase/MAPK signalling network underscoring the crucial importance of a sensitive polarized tip growth apparatus for successful mycoparasitism.

Download Full-text

Antisense oligonucleotides against aldehyde dehydrogenase 3 inhibit hepatoma cell proliferation by affecting MAP kinases

Chemico-Biological Interactions ◽

10.1016/s0009-2797(02)00170-9 ◽

2003 ◽

Vol 143-144 ◽

pp. 37-43 ◽

Cited By ~ 10

Author(s):

Giuliana Muzio ◽

Antonella Trombetta ◽

Germana Martinasso ◽

Rosa A Canuto ◽

Marina Maggiora

Keyword(s):

Cell Proliferation ◽

Aldehyde Dehydrogenase ◽

Antisense Oligonucleotides ◽

Map Kinases ◽

Hepatoma Cell

Download Full-text

Differential Effects of Toll-Like Receptor Activation and Differential Mediation by MAP Kinases of Immune Responses in Microglial Cells

Cellular and Molecular Neurobiology ◽

10.1007/s10571-021-01127-x ◽

2021 ◽

Author(s):

Jaedeok Kwon ◽

Christos Arsenis ◽

Maria Suessmilch ◽

Alison McColl ◽

Jonathan Cavanagh ◽

...

Keyword(s):

Map Kinase ◽

Microglial Activation ◽

Map Kinases ◽

Mrna Level ◽

Cell Types ◽

Receptor Activation ◽

Microglial Cells ◽

Toll Like Receptor ◽

Disease States ◽

Nitrite Production

AbstractMicroglial activation is believed to play a role in many psychiatric and neurodegenerative diseases. Based largely on evidence from other cell types, it is widely thought that MAP kinase (ERK, JNK and p38) signalling pathways contribute strongly to microglial activation following immune stimuli acting on toll-like receptor (TLR) 3 or TLR4. We report here that exposure of SimA9 mouse microglial cell line to immune mimetics stimulating TLR4 (lipopolysaccharide—LPS) or TLR7/8 (resiquimod/R848), results in marked MAP kinase activation, followed by induction of nitric oxide synthase, and various cytokines/chemokines. However, in contrast to TLR4 or TLR7/8 stimulation, very few effects of TLR3 stimulation by poly-inosine/cytidine (polyI:C) were detected. Induction of chemokines/cytokines at the mRNA level by LPS and resiquimod were, in general, only marginally affected by MAP kinase inhibition, and expression of TNF, Ccl2 and Ccl5 mRNAs, along with nitrite production, were enhanced by p38 inhibition in a stimulus-specific manner. Selective JNK inhibition enhanced Ccl2 and Ccl5 release. Many distinct responses to stimulation of TLR4 and TLR7 were observed, with JNK mediating TNF protein induction by the latter but not the former, and suppressing Ccl5 release by the former but not the latter. These data reveal complex modulation by MAP kinases of microglial responses to immune challenge, including a dampening of some responses. They demonstrate that abnormal levels of JNK or p38 signalling in microglial cells will perturb their profile of cytokine and chemokine release, potentially contributing to abnormal inflammatory patterns in CNS disease states.

Download Full-text

Signal-mediated localization of Candida albicans pheromone response pathway components

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkaa033 ◽

2020 ◽

Author(s):

Anna Carolina Borges Pereira Costa ◽

Raha Parvizi Omran ◽

Chris Law ◽

Vanessa Dumeaux ◽

Malcolm Whiteway

Keyword(s):

Candida Albicans ◽

Map Kinase ◽

Nuclear Localization ◽

Map Kinases ◽

Critical Role ◽

Cell Periphery ◽

Pheromone Response ◽

Pheromone Response Pathway ◽

Localization Signal ◽

In Cells

Abstract Candida albicans opaque cells release pheromones to stimulate cells of opposite mating type to activate their pheromone response pathway. Although this fungal pathogen shares orthologous proteins involved in the process with Saccharomyces cerevisiae, the pathway in each organism has unique characteristics. We have used GFP-tagged fusion proteins to investigate the localization of the scaffold protein Cst5, as well as the MAP kinases Cek1 and Cek2, during pheromone response in C. albicans. In wild-type cells, pheromone treatment directed Cst5-GFP to surface puncta concentrated at the tips of mating projections. These puncta failed to form in cells defective in either the Gα or β subunits. However, they still formed in response to pheromone in cells missing Ste11, but with the puncta distributed around the cell periphery in the absence of mating projections. These puncta were absent from hst7Δ/Δ cells, but could be detected in the ste11Δ/Δ hst7Δ/Δ double mutant. Cek2-GFP showed a strong nuclear localization late in the response, consistent with a role in adaptation, while Cek1-GFP showed a weaker, but early increase in nuclear localization after pheromone treatment. Activation loop phosphorylation of both Cek1 and Cek2 required the presence of Ste11. In contrast to Cek2-GFP, which showed no localization signal in ste11Δ/Δ cells, Cek1-GFP showed enhanced nuclear localization that was pheromone independent in the ste11Δ/Δ mutant. The results are consistent with CaSte11 facilitating Hst7-mediated MAP kinase phosphorylation and also playing a potentially critical role in both MAP kinase and Cst5 scaffold localization.

Download Full-text

Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

International Journal of Molecular Sciences ◽

10.3390/ijms22094717 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4717

Author(s):

Jin-Young Lee ◽

Da-Ae Kim ◽

Eun-Young Kim ◽

Eun-Ju Chang ◽

So-Jeong Park ◽

...

Keyword(s):

Bone Resorption ◽

Bone Formation ◽

Map Kinases ◽

Osteoclast Differentiation ◽

Dependent Manner ◽

Dual Action ◽

Dose Dependent ◽

Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

Download Full-text

Endogenous retrovirus-encoded Syncytin-2 contributes to exosome-mediated immunosuppression of T cells†

Biology of Reproduction ◽

10.1093/biolre/ioz124 ◽

2019 ◽

Cited By ~ 5

Author(s):

Adjimon G Lokossou ◽

Caroline Toudic ◽

Phuong Trang Nguyen ◽

Xavier Elisseeff ◽

Amandine Vargas ◽

...

Keyword(s):

T Cells ◽

T Cell Activation ◽

Map Kinases ◽

Cell Activation ◽

Mononuclear Cells ◽

Immune Cell ◽

Endogenous Retrovirus ◽

Jurkat Cells ◽

Peripheral Blood Mononuclear ◽

Interfering Rna

Abstract Modulation of the activation status of immune cell populations during pregnancy depends on placental villous cytotrophoblast (VCT) cells and the syncytiotrophoblast (STB). Failure in the establishment of this immunoregulatory function leads to pregnancy complications. Our laboratory has been studying Syncytin-2 (Syn-2), an endogenous retroviral protein expressed in placenta and on the surface of placental exosomes. This protein plays an important role not only in STB formation through its fusogenic properties, but also through its immunosuppressive domain (ISD). Considering that Syn-2 expression is importantly reduced in preeclamptic placentas, we were interested in addressing its possible immunoregulatory effects on T cells. Activated Jurkat T cells and peripheral blood mononuclear cells (PBMCs) were treated with monomeric or dimerized version of a control or a Syn-2 ISD peptide. Change in phosphorylation levels of ERK1/2 MAP kinases was selectively noted in Jurkat cells treated with the dimerized ISD peptide. Upon incubation with the dimerized Syn-2 ISD peptide, significant reduction in Th1 cytokine production was further demonstrated by ELISA and Human Th1/Th2 Panel Multi-Analyte Flow Assay. To determine if exosome-associated Syn-2 could also be immunosuppressive placental exosomes were incubated with activated Jurkat and PBMCs. Quantification of Th1 cytokines in the supernatants revealed severe reduction in T cell activation. Interestingly, exosomes from Syn-2-silenced VCT incubated with PBMCs were less suppressive when compared with exosome derived from VCT transfected with control small interfering RNA (siRNA). Our results suggest that Syn-2 is an important immune regulator both locally and systemically, via its association with placental exosomes.

Download Full-text