A nuclear protein NsiA from Epichloë festucae interacts with a MAP kinase MpkB and regulates the expression of genes required for symbiotic infection and hyphal cell fusion

2020 ◽  
Vol 114 (4) ◽  
pp. 626-640 ◽  
Author(s):  
Aiko Tanaka ◽  
Shota Kamiya ◽  
Yoshino Ozaki ◽  
Shinichi Kameoka ◽  
Yuka Kayano ◽  
...  
Keyword(s):  
Map Kinase ◽  
Cell Fusion ◽  
Nuclear Protein ◽  
Hyphal Cell ◽  
Epichloë Festucae ◽  
Expression Of Genes

scholarly journals The MAP kinase TVK1 regulates conidiation, hydrophobicity and the expression of genes encoding cell wall proteins in the fungus Trichoderma virens

Microbiology ◽  
2007 ◽  
Vol 153 (7) ◽  
pp. 2137-2147 ◽  
Author(s):  
Artemio Mendoza-Mendoza ◽  
Teresa. Rosales-Saavedra ◽  
Carlos. Cortés ◽  
Verónica. Castellanos-Juárez ◽  
Pedro. Martínez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Map Kinase ◽  
Cell Wall Proteins ◽  
Trichoderma Virens ◽  
Expression Of Genes ◽  
Genes Encoding

scholarly journals Separating myoblast differentiation from muscle cell fusion using IGF-I and the p38 MAP kinase inhibitor SB202190

2015 ◽  
Vol 309 (7) ◽  
pp. C491-C500 ◽  
Author(s):  
Samantha Gardner ◽  
Sean M. Gross ◽  
Larry L. David ◽  
John E. Klimek ◽  
Peter Rotwein
Keyword(s):  
Growth Factor ◽  
Map Kinase ◽  
Cell Fusion ◽  
Muscle Cell ◽  
Map Kinases ◽  
Kinase Inhibitor ◽  
P38 Map Kinase ◽  
Myoblast Differentiation ◽  
Igf I ◽  
Muscle Biology

The p38 MAP kinases play critical roles in skeletal muscle biology, but the specific processes regulated by these kinases remain poorly defined. Here we find that activity of p38α/β is important not only in early phases of myoblast differentiation, but also in later stages of myocyte fusion and myofibrillogenesis. By treatment of C2 myoblasts with the promyogenic growth factor insulin-like growth factor (IGF)-I, the early block in differentiation imposed by the p38 chemical inhibitor SB202190 could be overcome. Yet, under these conditions, IGF-I could not prevent the later impairment of muscle cell fusion, as marked by the nearly complete absence of multinucleated myofibers. Removal of SB202190 from the medium of differentiating myoblasts reversed the fusion block, as multinucleated myofibers were detected several hours later and reached ∼90% of the culture within 30 h. Analysis by quantitative mass spectroscopy of proteins that changed in abundance following removal of the inhibitor revealed a cohort of upregulated muscle-enriched molecules that may be important for both myofibrillogenesis and fusion. We have thus developed a model system that allows separation of myoblast differentiation from muscle cell fusion and should be useful in identifying specific steps regulated by p38 MAP kinase-mediated signaling in myogenesis.

scholarly journals Accumulation of specific sterol precursors targets a MAP kinase cascade mediating cell–cell recognition and fusion

2016 ◽  
Vol 113 (42) ◽  
pp. 11877-11882 ◽  
Author(s):  
Martin Weichert ◽  
Alexander Lichius ◽  
Bert-Ewald Priegnitz ◽  
Ulrike Brandt ◽  
Johannes Gottschalk ◽  
...  
Keyword(s):  
Double Bond ◽  
Map Kinase ◽  
Cell Fusion ◽  
Cell Communication ◽  
Eukaryotic Cell ◽  
Side Chain ◽  
Signaling Mechanism ◽  
Aliphatic Side Chain ◽  
Mitogen Activated Protein ◽  
Cell Cell

Sterols are vital components of eukaryotic cell membranes. Defects in sterol biosynthesis, which result in the accumulation of precursor molecules, are commonly associated with cellular disorders and disease. However, the effects of these sterol precursors on the metabolism, signaling, and behavior of cells are only poorly understood. In this study, we show that the accumulation of only ergosterol precursors with a conjugated double bond in their aliphatic side chain specifically disrupts cell–cell communication and fusion in the fungus Neurospora crassa. Genetically identical germinating spores of this fungus undergo cell–cell fusion, thereby forming a highly interconnected supracellular network during colony initiation. Before fusion, the cells use an unusual signaling mechanism that involves the coordinated and alternating switching between signal sending and receiving states of the two fusion partners. Accumulation of only ergosterol precursors with a conjugated double bond in their aliphatic side chain disrupts this coordinated cell–cell communication and suppresses cell fusion. These specific sterol precursors target a single ERK-like mitogen-activated protein (MAP) kinase (MAK-1)-signaling cascade, whereas a second MAP kinase pathway (MAK-2), which is also involved in cell fusion, is unaffected. These observations indicate that a minor specific change in sterol structure can exert a strong detrimental effect on a key signaling pathway of the cell, resulting in the absence of cell fusion.

Effects of mitogen-activated protein kinases on nuclear protein importThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 469-475 ◽  
Author(s):  
Randolph S. Faustino ◽  
Delphine C. Rousseau ◽  
Melanie N. Landry ◽  
Annette L. Kostenuk ◽  
Grant N. Pierce
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Protein Import ◽  
Nuclear Protein ◽  
Muscle Cells ◽  
Inhibitory Effects ◽  
Permeabilized Cell ◽  
A Cell ◽  
Nuclear Protein Import

ERK-2 MAP kinase activation induces inhibitory effects on nuclear protein import in vascular smooth muscle cells. The mechanism and characteristics of this effect of ERK-2 were investigated. An unusual dose-dependent effect of ERK-2 on nuclear protein import was identified. At higher concentrations (1 μg/mL) of ERK-2, nuclear protein import was stimulated, whereas lower concentrations (0.04 μg/mL) inhibited import. Intermediate concentrations exerted intermediate effects. The stimulatory and inhibitory effects at the 2 different ERK-2 concentrations were observed in both conventional, permeabilized cell assays of nuclear protein import and with in situ microinjection of smooth muscle cells. The biphasic effects of ERK-2 on import were also found for the other 2 members of the MAPK family, p38 and JNK. RanGAP was identified by structural analysis as a candidate target protein responsible for mediating the effects of ERK-2. After pretreatment with high concentrations of ERK-2, RanGAP activity was significantly increased by ~50%. In contrast, low concentrations of ERK-2 significantly attenuated RanGAP activity. These results demonstrate that all 3 members of the MAPK family can alter nuclear protein import in opposite directions depending upon the concentration of ERK-2 used. RanGAP represents the MAP kinase target whereby nuclear transport can be stimulated or inhibited.

scholarly journals A network of MAP-Kinase pathways and transcription factors regulates cell-to-cell communication and cell wall integrity in Neurospora crassa

2018 ◽  
Author(s):  
Monika S. Fischer ◽  
Vincent W. Wu ◽  
Ji E. Lee ◽  
Ronan C. O’Malley ◽  
N. Louise Glass
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Map Kinase ◽  
Neurospora Crassa ◽  
Cell Fusion ◽  
Regulatory Network ◽  
Cell Communication ◽  
Cell Wall Integrity ◽  
Cell Integrity ◽  
Map Kinase Pathways

ABSTRACTMaintenance of cell integrity and cell-to-cell communication are fundamental biological processes. Filamentous fungi, such as Neurospora crassa, depend on communication to locate compatible cells, coordinate cell fusion, and establish a robust hyphal network. Two MAP-Kinase pathways are essential for communication and cell fusion in N. crassa; the Cell Wall Integrity/MAK-1 pathway and the MAK-2 (signal response) pathway. Previous studies have demonstrated several points of cross talk between the MAK-1 and MAK-2 pathways, which is likely necessary for oordinating chemotropic growth toward an extracellular signal, and then mediating cell fusion. Canonical MAP-Kinase pathways begin with signal reception and end with a transcriptional response. Two transcription factors, ADV-1 and PP-1, are essential for communication and cell fusion. PP-1 is the conserved target of MAK-2, while it is unclear what targets ADV-1. We did RNAseq on Δadv-1, Δpp-1, and wild-type cells and found that ADV-1 and PP-1 have a shared regulon including many genes required for communication, cell fusion, growth, development, and stress response. We identified ADV-1 and PP-1 binding sites across the genome by adapting the in vitro method of DNA-Affinity Purification sequencing (DAP-seq) for N. crassa. To elucidate the regulatory network, we misexpressed each transcription factor in each upstream MAPK deletion mutant. Misexpression of adv-1 was sufficient to fully suppress the phenotype of the Δpp-1 mutant and partially suppress the phenotype of the Δmak-1 mutant. Collectively, our data demonstrate that the MAK-1-ADV-1 and MAK-2- PP-1 pathways form a tight regulatory network that maintains cell integrity and mediates communication and cell fusion.

scholarly journals Insulin regulation of mitogen-activated protein kinase kinase (MEK), mitogen-activated protein kinase and casein kinase in the cell nucleus: a possible role in the regulation of gene expression

1997 ◽  
Vol 323 (3) ◽  
pp. 621-627 ◽  
Author(s):  
Sung-Jin KIM ◽  
Ronald C. KAHN
Keyword(s):  
Protein Kinase ◽  
Map Kinase ◽  
Map Kinases ◽  
Nuclear Protein ◽  
Insulin Signalling ◽  
Receptor Activation ◽  
Casein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Intact Cells ◽  
Mitogen Activated Protein

After insulin receptor activation, many cytoplasmic enzymes, including mitogen-activated protein (MAP) kinase, MAP kinase kinase (MEK) and casein kinase II (CKII) are activated, but exactly how insulin signalling progresses to the nucleus remains poorly understood. In Chinese hamster ovary cells overexpressing human insulin receptors [CHO(Hirc)], MEK, CKII and the MAP kinases ERK I and ERK II can be detected by immunoblotting in the nucleus, as well as in the cytoplasm, in the unstimulated state. Nuclear localization of MAP kinase is also observed in 3T3-F442A adipocytes, NIH-3T3 cells and Fao hepatoma cells, whereas MEK is found in the nucleus only in Fao and CHO cells. Insulin treatment for 5–30 min induces a translocation of MEK from the cytoplasm to the nucleus, whereas the MAP kinases and CKII are not translocated into the nucleus in response to insulin during this period. However, nuclear MAP kinase and CKII activities increase by 2–3-fold within 1–10 min after stimulation with insulin. By using gel-shift assays, it has been shown that insulin also stimulates nuclear protein binding to an AP-1 site with kinetics similar to MEK translocation and MAP kinase and CKII activation. Treatment of the extracts in vitro with protein phosphatase 2A or treatment of the intact cells with 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole, a cell-permeable inhibitor of CKII, almost completely blocks the insulin-induced DNA-binding activity, whereas incubation of cells with a MEK inhibitor produces only a slight decrease. These results suggest that insulin signalling results in the activation of serine kinases in the nucleus via two pathways: (1) insulin stimulates the nuclear translocation of some kinases, such as MEK, which might directly phosphorylate nuclear protein substrates or activate other nuclear kinases, and (2) insulin activates nuclear kinases without translocation. The latter is true of CKII, which seems to regulate the binding of nuclear proteins to the AP-1 site, possibly by phosphorylation of AP-1 transcription factors.

scholarly journals Phosphatidic acid produced by phospholipase D is required for hyphal cell‐cell fusion and fungal‐plant symbiosis

2020 ◽  
Vol 113 (6) ◽  
pp. 1101-1121 ◽  
Author(s):  
Berit Hassing ◽  
Carla J. Eaton ◽  
David Winter ◽  
Kimberly A. Green ◽  
Ulrike Brandt ◽  
...  
Keyword(s):  
Phosphatidic Acid ◽  
Cell Fusion ◽  
Phospholipase D ◽  
Hyphal Cell ◽  
Cell Cell
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