scholarly journals Wounding and insect feeding trigger two independent MAPK pathways with distinct regulation and kinetics

2019 ◽  
Author(s):  
Cécile Sözen ◽  
Sebastian T. Schenk ◽  
Marie Boudsocq ◽  
Camille Chardin ◽  
Marilia Almeida-Trapp ◽  
...  
Keyword(s):  
Insect Feeding ◽  
Independent Manner ◽  
Clade C ◽  
Short And Long Term ◽  
Abiotic And Biotic Factors ◽  
Parallel Activation ◽  
Rapid Signaling ◽  
Complex Signaling ◽  
Ja Signaling ◽  
Rapid Activation

AbstractWounding is caused by abiotic and biotic factors and triggers complex short- and long-term responses at the local and systemic level. These responses are under the control of complex signaling pathways, which are still poorly understood. Here, we show that the rapid activation of MKK4/5-MPK3/6 by wounding is independent of jasmonic acid (JA) signaling and that, contrary to what happens in tobacco, this fast module does not control wound-triggered JA accumulation in Arabidopsis. We also demonstrate that a second MAPK module, constituted by MKK3 and the clade-C MAPKs MPK1/2/7, is activated by wounding in an independent manner. We provide evidence that the activation of this MKK3-MPK1/2/7 module occurs mainly through wound-induced JA production via the transcriptional regulation of upstream clade-III MAP3Ks and particularly MAP3K14. We show that mkk3 mutant plants are more susceptible to the larvae of the generalist lepidopteran herbivore Spodoptera littoralis, indicating that the MKK3-MPK1/2/7 module is involved in counteracting insect feeding.One sentence summaryWounding induces the parallel activation of a rapid signaling module (MKK4/5-MPK3/6) and a JA-dependent slow one (MAP3K14-MKK3-MPK1/2/7/14) to restrict insect feeding.

scholarly journals G Proteins and GPCRs in C. elegans Development: A Story of Mutual Infidelity

2018 ◽  
Vol 6 (4) ◽  
pp. 28 ◽  
Author(s):  
Daniel Matúš ◽  
Simone Prömel
Keyword(s):  
Signaling Pathways ◽  
G Protein ◽  
G Proteins ◽  
Cell Polarity ◽  
Protein Activity ◽  
Independent Manner ◽  
C Elegans ◽  
Downstream Effectors ◽  
Complex Signaling ◽  
G Protein Coupled

Many vital processes during C. elegans development, especially the establishment and maintenance of cell polarity in embryogenesis, are controlled by complex signaling pathways. G protein-coupled receptors (GPCRs), such as the four Frizzled family Wnt receptors, are linchpins in regulating and orchestrating several of these mechanisms. However, despite being GPCRs, which usually couple to G proteins, these receptors do not seem to activate classical heterotrimeric G protein-mediated signaling cascades. The view on signaling during embryogenesis is further complicated by the fact that heterotrimeric G proteins do play essential roles in cell polarity during embryogenesis, but their activity is modulated in a predominantly GPCR-independent manner via G protein regulators such as GEFs GAPs and GDIs. Further, the triggered downstream effectors are not typical. Only very few GPCR-dependent and G protein-mediated signaling pathways have been unambiguously defined in this context. This unusual and highly intriguing concept of separating GPCR function and G-protein activity, which is not restricted to embryogenesis in C. elegans but can also be found in other organisms, allows for essential and multi-faceted ways of regulating cellular communication and response. Although its relevance cannot be debated, its impact is still poorly discussed, and C. elegans is an ideal model to understand the underlying principles.

scholarly journals An effector from cotton bollworm oral secretion impairs host plant defense signaling

2019 ◽  
Vol 116 (28) ◽  
pp. 14331-14338 ◽  
Author(s):  
Chun-Yu Chen ◽  
Yao-Qian Liu ◽  
Wei-Meng Song ◽  
Dian-Yang Chen ◽  
Fang-Yan Chen ◽  
...  
Keyword(s):  
Plant Defense ◽  
Host Plants ◽  
Crop Productivity ◽  
Cotton Bollworm ◽  
Plant Leaves ◽  
Oral Secretion ◽  
Insect Feeding ◽  
Working Mechanism ◽  
Lepidopteran Insect ◽  
Ja Signaling

Insects have evolved effectors to conquer plant defense. Most known insect effectors are isolated from sucking insects, and examples from chewing insects are limited. Moreover, the targets of insect effectors in host plants remain unknown. Here, we address a chewing insect effector and its working mechanism. Cotton bollworm (Helicoverpa armigera) is a lepidopteran insect widely existing in nature and severely affecting crop productivity. We isolated an effector named HARP1 fromH. armigeraoral secretion (OS). HARP1 was released from larvae to plant leaves during feeding and entered into the plant cells through wounding sites. Expression of HARP1 inArabidopsismitigated the global expression of wounding and jasmonate (JA) responsive genes and rendered the plants more susceptible to insect feeding. HARP1 directly interacted with JASMONATE-ZIM-domain (JAZ) repressors to prevent the COI1-mediated JAZ degradation, thus blocking JA signaling transduction. HARP1-like proteins have conserved function as effectors in noctuidae, and these types of effectors might contribute to insect adaptation to host plants during coevolution.

scholarly journals Sex-dependent and -independent transcriptional changes during haploid phase gametogenesis in the sugar kelpSaccharina latissima

2019 ◽  
Author(s):  
Gareth A Pearson ◽  
Neusa Martins ◽  
Pedro Madeira ◽  
Ester A Serrão ◽  
Inka Bartsch
Keyword(s):  
Ribosome Biogenesis ◽  
Mitotic Cell ◽  
Saccharina Latissima ◽  
Independent Manner ◽  
Coordinate Gene Expression ◽  
Core Set ◽  
Transcriptional Changes ◽  
Genome Level ◽  
Male Specific ◽  
Rapid Activation

AbstractIn haplodiplontic lineages, sexual reproduction occurs in haploid parents without meiosis. Although widespread in multicellular lineages such as brown algae (Phaeophyceae), haplodiplontic gametogenesis has been little studied at the molecular level. We addressed this by generating an annotated reference transcriptome for the gametophytic phase of the sugar kelp,Saccharina latissima. Transcriptional profiles of microscopic male and female gametophytes were analysed at four time points during the transition from vegetative growth to gametogenesis. Gametogenic signals resulting from a switch in culture irradiance from red to white light activated a core set of genes in a sex-independent manner, involving rapid activation of ribosome biogenesis, transcription and translation related pathways, with several acting at the post-transcriptional or post-translational level. Additional genes regulating nutrient acquisition and key carbohydrate-energy pathways were also identified. Candidate sex-biased genes under gametogenic conditions had potentially key roles in controlling female- and male-specific gametogenesis. Among these were several sex-biased or - specific E3 ubiquitin-protein ligases that may have important regulatory roles. Females specifically expressed several genes that coordinate gene expression and/or protein degradation, and the synthesis of inositol-containing compounds. Other female-biased genes supported parallels with oogenesis in divergent multicellular lineages, in particular reactive oxygen signalling via an NADPH-oxidase. Males specifically expressed the hypothesised brown algal sex-determining factor. Male-biased expression mainly involved upregulation of genes that control mitotic cell proliferation and spermatogenesis in other systems, as well as multiple flagella-related genes. Our data and results enhance genome-level understanding of gametogenesis in this ecologically and economically important multicellular lineage.

Peptide Coated Titanium Rods Show Increased Bone Formation in a Rat Femur Model

1998 ◽  
Vol 550 ◽  
Author(s):  
D.M. Ferris ◽  
G.D. Moodie ◽  
P.M. Dimond ◽  
M.G. Ehrlich ◽  
R.F. Valentini
Keyword(s):  
Cell Receptor ◽  
Peptide Sequence ◽  
Pull Out ◽  
Significant Difference ◽  
Short And Long Term ◽  
And Function ◽  
Complex Signaling ◽  
Control Rods

AbstractIn vitro, groups have demonstrated that peptide modified surfaces influence short and long term cell responses like attachment, shape and function via cell receptors known as integrins. These receptors translate information to the nucleus via sets of complex signaling pathways. Little is known about the ability of these surfaces to influence the inherently complex in vivo environment, however. The present study was designed to evaluate the quality and quantity of new bone formed in response to gold coated titanium rods modified with the peptide sequence Arg-Gly-Asp-Cys (RGDC). Quantitative histomorphometric analysis of histologic sections perpendicular to the implant long axis showed a thicker (P < 0.01) shell of new bone formed in response to peptide modified implants (26.2 microns ± 1.9 vs. 20.5 microns ± 2.9) as early as 2 weeks. Mechanical pull-out testing conducted at 4 weeks revealed the average pull-out force of peptide modified rods was 38% greater than gold control rods. The significant difference in the thickness of new bone formed around the implant was maintained at 4 weeks (32.7 microns ± 4.6 vs. 22.6 microns ± 4.0). These results demonstrate the feasibility of developing peptide coated biomaterials designed to elicit a host response at the cell receptor level.

Circulating B-cell chronic lymphocytic leukemia cells display impaired migration to lymph nodes due to reduced LFA-1 expression

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3135-3135
Author(s):  
Tanja Nicole Hartmann ◽  
Valentin Grabovsky ◽  
Wei Wang ◽  
Petra Desch ◽  
Stefan Wollner ◽  
...  
Keyword(s):  
B Cells ◽  
Lymph Nodes ◽  
B Cell ◽  
Lymphocytic Leukemia ◽  
Dependent Manner ◽  
Independent Manner ◽  
Immunodeficient Mice ◽  
Chemokine Cxcl12 ◽  
Rapid Activation

Abstract Homing to secondary lymphoid organs and re-entry to bone marrow (BM) are central aspects of leukemic pathophysiology. We investigated the roles of the two major lymphocyte integrins LFA-1 and VLA-4 on B-cell chronic lymphocytic leukaemia (CLL) cells in these processes. We found that CLL cells expressed significantly reduced LFA-1 due to low beta2 integrin transcripts and displayed diminished adhesiveness to ICAM-1-expressing endothelium in vitro. VLA-4 expression was heterogenous but underwent rapid activation by the BM chemokine CXCL12. Nevertheless, CLL cells failed to transmigrate across VCAM-1, ICAM-1 and CXCL12 expressing endothelium due to their deficient LFA-1 expression. Furthermore, when injected into tail veins of immunodeficient mice, normal B cells rapidly homed to lymph nodes (LNs) in a LFA-1 dependent manner whereas CLL cells did not. CLL alike normal B lymphocytes used VLA-4 rather than LFA-1 to reenter the BM. In contrast, both normal and CLL B cells homed to mice spleen in an LFA-1- and VLA-4-independent manner. Our results suggest that CLL cells are deficient in LFA-1-dependent trafficking to LNs but residual subsets can still re-enter the BM. Integrin blocking could be therefore an efficient strategy to prevent circulating CLL cells from reaching prosurvival niches in LNs and BM and directing these cells to the spleen.

scholarly journals Generalized nucleation and looping model for epigenetic memory of histone modifications

2016 ◽  
Vol 113 (29) ◽  
pp. E4180-E4189 ◽  
Author(s):  
Fabian Erdel ◽  
Eric C. Greene
Keyword(s):  
Histone Modifications ◽  
Domain Size ◽  
Biochemical Properties ◽  
Long Term Memory ◽  
Epigenetic Memory ◽  
Independent Manner ◽  
Position Effects ◽  
Histone Modifiers ◽  
Short And Long Term ◽  
Underlying Mechanisms

Histone modifications can redistribute along the genome in a sequence-independent manner, giving rise to chromatin position effects and epigenetic memory. The underlying mechanisms shape the endogenous chromatin landscape and determine its response to ectopically targeted histone modifiers. Here, we simulate linear and looping-driven spreading of histone modifications and compare both models to recent experiments on histone methylation in fission yeast. We find that a generalized nucleation-and-looping mechanism describes key observations on engineered and endogenous methylation domains including intrinsic spatial confinement, independent regulation of domain size and memory, variegation in the absence of antagonists, and coexistence of short- and long-term memory at loci with weak and strong constitutive nucleation. These findings support a straightforward relationship between the biochemical properties of chromatin modifiers and the spatiotemporal modification pattern. The proposed mechanism gives rise to a phase diagram for cellular memory that may be generally applicable to explain epigenetic phenomena across different species.

scholarly journals Integrated transcriptome and proteome analysis reveals complex regulatory mechanism of cotton in response to salt stress

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Lin CHEN ◽  
Heng SUN ◽  
Jie KONG ◽  
Haijiang XU ◽  
Xiyan YANG
Keyword(s):  
Salt Stress ◽  
Proteome Analysis ◽  
Mapk Signaling ◽  
Differentially Expressed ◽  
Mitogen Activated Protein Kinase ◽  
Integrated Analysis ◽  
Yield And Quality ◽  
Mitogen Activated Protein ◽  
Complex Signaling ◽  
Ja Signaling

Abstract Background Soil salt stress seriously restricts the yield and quality of cotton worldwide. To investigate the molecular mechanism of cotton response to salt stress, a main cultivated variety Gossypium hirsutum L. acc. Xinluzhong 54 was used to perform transcriptome and proteome integrated analysis. Results Through transcriptome analysis in cotton leaves under salt stress for 0 h (T0), 3 h (T3) and 12 h (T12), we identified 8 436, 11 628 and 6 311 differentially expressed genes (DEGs) in T3 vs. T0, T12 vs. T0 and T12 vs. T3, respectively. A total of 459 differentially expressed proteins (DEPs) were identified by proteomic analysis, of which 273, 99 and 260 DEPs were identified in T3 vs. T0, T12 vs. T0 and T12 vs. T3, respectively. Metabolic pathways, biosynthesis of secondary metabolites, photosynthesis and plant hormone signal transduction were enriched among the identified DEGs or DEPs. Detail analysis of the DEGs or DEPs revealed that complex signaling pathways, such as abscisic acid (ABA) and jasmonic acid (JA) signaling, calcium signaling, mitogen-activated protein kinase (MAPK) signaling cascade, transcription factors, activation of antioxidant and ion transporters, were participated in regulating salt response in cotton. Conclusions Our research not only contributed to understand the mechanism of cotton response to salt stress, but also identified nine candidate genes, which might be useful for molecular breeding to improve salt-tolerance in cotton.

Short- and Long-Term Results of Total vs Subtotal Thyroid- ectomies in the Surgical Treatment of Graves' Disease

Swiss Surgery ◽  
2001 ◽  
Vol 7 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Robert ◽  
Mariéthoz ◽  
Pache ◽  
Bertin ◽  
Caulfield ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Nerve Palsy ◽  
Recurrent Laryngeal Nerve Palsy ◽  
Laryngeal Nerve ◽  
Long Term Results ◽  
Graves Disease ◽  
Laryngeal Nerve Palsy ◽  
Short And Long Term

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

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