scholarly journals The AGC protein kinase UNICORN controls planar growth by attenuating PDK1 in Arabidopsis thaliana

2018 ◽  
Author(s):  
Sebastian Scholz ◽  
Janys Pleßmann ◽  
Regina Hüttl ◽  
Katrin Wassmer ◽  
Balaji Enugutti ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Seed Coat ◽  
Stress Responses ◽  
Biological Data ◽  
Growth Patterns ◽  
Cellular Growth ◽  
Distinct Cell ◽  
Cell Layers ◽  
Planar Growth

AbstractTissue morphogenesis critically depends on the coordination of cellular growth patterns. In plants, many organs consist of clonally distinct cell layers, such as the epidermis, whose cells undergo divisions that are oriented along the plane of the layer. The developmental control of such planar growth is poorly understood. We have previously identified the Arabidopsis AGCVIII-class protein kinase UNICORN (UCN) as a central regulator of this process. Plants lacking UCN activity show spontaneous formation of ectopic multicellular protrusions in integuments and malformed petals indicating that UCN suppresses uncontrolled growth in those tissues. In the current model UCN regulates planar growth of integuments in part by directly repressing the putative transcription factor ABERRANT TESTA SHAPE (ATS). Here we report on the identification of 3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE 1 (PDK1) as a novel factor involved in UCN-mediated growth control. PDK1 constitutes a basic component of signaling mediated by AGC protein kinases throughout eukaryotes. Arabidopsis PDK1 is implied in stress responses and growth promotion. Here we show that loss-of-function mutations in PDK1 suppress aberrant growth in integuments and petals of ucn mutants. Additional genetic, in vitro, and cell biological data support the view that UCN functions by repressing PDK1. Furthermore, our data indicate that PDK1 is indirectly required for deregulated growth caused by ATS overexpression. Our findings support a model proposing that UCN suppresses ectopic growth in integuments through two independent processes: the attenuation of the protein kinase PDK1 in the cytoplasm and the repression of the transcription factor ATS in the nucleus.Author SummaryPlant organs, such as petals or roots, are composites of distinct cell layers. As a rule, cells making up a layer, for example the epidermis, the outermost layer of a tissue, divide “within the plane” of the layer. This cellular behavior results in the two-dimensional sheet-like or planar growth of the cell layer. The mechanism orchestrating such a growth pattern is poorly understood. In particular, it is unclear how uncontrolled and “out-of-plane” growth is avoided. Here we provide insight into this process. Our data indicate that higher than normal activity of a central regulator of growth and stress responses results in wavy and malformed petals and in protrusion-like aberrant outgrowths in the tissue that will develop into the seed coat. It is therefore important to keep this factor in check to allow proper formation of those tissues. We further show that a protein called UNICORN attenuates the activity of this regulator thereby ensuring the sheet-like growth of young petals or the developing seed coat.

Physical aspects of tissue evagination and biological form

1977 ◽  
Vol 10 (4) ◽  
pp. 529-593 ◽  
Author(s):  
Alfred Gierer
Keyword(s):  
Growth Patterns ◽  
Cellular Material ◽  
Complex Interplay ◽  
Cell Sheets ◽  
Distinct Cell ◽  
Biological Form ◽  
Cell Layers ◽  
Flat Cell ◽  
Solid Tissues ◽  
Basic Features

The form of multicellular animals and their organs is mainly defined by the curvature of cell layers. They are boundaries for solid tissues; and some organs and organisms consist mainly of distinct cell layers (Fig. I a). The form of adult organisms results from a complex interplay of tissue evagination, growth patterns, production of and interaction with extra-cellular material, and other effects; but the rudiments and basic features of the forms produced can often be traced back to processes of evagination or invagination of nearly flat cell sheets at defined locations in the course of embryogenesis.

scholarly journals A novel family of dehydrin-like proteins is involved in stress response in the human fungal pathogenAspergillus fumigatus

2011 ◽  
Vol 22 (11) ◽  
pp. 1896-1906 ◽  
Author(s):  
Joanne Wong Sak Hoi ◽  
Claude Lamarre ◽  
Rémi Beau ◽  
Isabelle Meneau ◽  
Adokiye Berepiki ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Stress Responses ◽  
Fluorescent Protein ◽  
Mapk Pathway ◽  
Experimental Models ◽  
Mitogen Activated Protein Kinase ◽  
Bzip Transcription Factor ◽  
Mitogen Activated Protein ◽  
Protective Proteins

 During a search for genes controlling conidial dormancy in Aspergillus fumigatus, two dehydrin-like genes, DprA and DprB, were identified. The deduced proteins had repeated stretches of 23 amino acids that contained a conserved dehydrin-like protein (DPR) motif. Disrupted DprAΔ mutants were hypersensitive to oxidative stress and to phagocytic killing, whereas DprBΔ mutants were impaired in osmotic and pH stress responses. However, no effect was observed on their pathogenicity in our experimental models of invasive aspergillosis. Molecular dissection of the signaling pathways acting upstream showed that expression of DprA was dependent on the stress-activated kinase SakA and the cyclic AMP-protein kinase A (cAMP-PKA) pathways, which activate the bZIP transcription factor AtfA, while expression of DprB was dependent on the SakA mitogen-activated protein kinase (MAPK) pathway, and the zinc finger transcription factor PacC. Fluorescent protein fusions showed that both proteins were associated with peroxisomes and the cytosol. Accordingly, DprA and DprB were important for peroxisome function. Our findings reveal a novel family of stress-protective proteins in A. fumigatus and, potentially, in filamentous ascomycetes.

scholarly journals Chordoma—Current Understanding and Modern Treatment Paradigms

2021 ◽  
Vol 10 (5) ◽  
pp. 1054
Author(s):  
Sean M. Barber ◽  
Saeed S. Sadrameli ◽  
Jonathan J. Lee ◽  
Jared S. Fridley ◽  
Bin S. Teh ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Growth Factor Receptor ◽  
Growth Patterns ◽  
Molecular Therapy ◽  
Mitogen Activated Protein Kinase ◽  
Low Grade ◽  
Ongoing Research ◽  
Mobile Spine ◽  
Modern Treatment

Chordoma is a low-grade notochordal tumor of the skull base, mobile spine and sacrum which behaves malignantly and confers a poor prognosis despite indolent growth patterns. These tumors often present late in the disease course, tend to encapsulate adjacent neurovascular anatomy, seed resection cavities, recur locally and respond poorly to radiotherapy and conventional chemotherapy, all of which make chordomas challenging to treat. Extent of surgical resection and adequacy of surgical margins are the most important prognostic factors and thus patients with chordoma should be cared for by a highly experienced, multi-disciplinary surgical team in a quaternary center. Ongoing research into the molecular pathophysiology of chordoma has led to the discovery of several pathways that may serve as potential targets for molecular therapy, including a multitude of receptor tyrosine kinases (e.g., platelet-derived growth factor receptor [PDGFR], epidermal growth factor receptor [EGFR]), downstream cascades (e.g., phosphoinositide 3-kinase [PI3K]/protein kinase B [Akt]/mechanistic target of rapamycin [mTOR]), brachyury—a transcription factor expressed ubiquitously in chordoma but not in other tissues—and the fibroblast growth factor [FGF]/mitogen-activated protein kinase kinase [MEK]/extracellular signal-regulated kinase [ERK] pathway. In this review article, the pathophysiology, diagnosis and modern treatment paradigms of chordoma will be discussed with an emphasis on the ongoing research and advances in the field that may lead to improved outcomes for patients with this challenging disease.

scholarly journals Potassium Control of Plant Functions: Ecological and Agricultural Implications

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 419
Author(s):  
Jordi Sardans ◽  
Josep Peñuelas
Keyword(s):  
Food Security ◽  
Stress Responses ◽  
Crop Production ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Wood Formation ◽  
Cellular Growth ◽  
Ecosystem Functions ◽  
Metabolite Transport ◽  
Physiological Functions

Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it is more difficult to link it to concrete metabolic pathways than nitrogen or phosphorus. Over the last two decades, many studies have reported on the role of K+ in several physiological functions, including controlling cellular growth and wood formation, xylem–phloem water content and movement, nutrient and metabolite transport, and stress responses. In this paper, we present an overview of contemporary findings associating K+ with various plant functions, emphasizing plant-mediated responses to environmental abiotic and biotic shifts and stresses by controlling transmembrane potentials and water, nutrient, and metabolite transport. These essential roles of K+ account for its high concentrations in the most active plant organs, such as leaves, and are consistent with the increasing number of ecological and agricultural studies that report K+ as a key element in the function and structure of terrestrial ecosystems, crop production, and global food security. We synthesized these roles from an integrated perspective, considering the metabolic and physiological functions of individual plants and their complex roles in terrestrial ecosystem functions and food security within the current context of ongoing global change. Thus, we provide a bridge between studies of K+ at the plant and ecological levels to ultimately claim that K+ should be considered at least at a level similar to N and P in terrestrial ecological studies.

scholarly journals Mitogen-Activated Protein Kinase Expression Profiling Revealed Its Role in Regulating Stress Responses in Potato (Solanum tuberosum)

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1371
Author(s):  
Madiha Zaynab ◽  
Athar Hussain ◽  
Yasir Sharif ◽  
Mahpara Fatima ◽  
Mateen Sajid ◽  
...  
Keyword(s):  
Solanum Tuberosum ◽  
Protein Kinase ◽  
Stress Responses ◽  
Expression Profiling ◽  
Regulatory Elements ◽  
Mitogen Activated Protein Kinase ◽  
High Expression ◽  
Primary Data ◽  
A Genome ◽  
Mitogen Activated Protein

Mitogen-activated protein kinase (MAPK) cascades are the universal signal transduction networks that regulate cell growth and development, hormone signaling, and other environmental stresses. However, their essential contribution to plant tolerance is very little known in the potato (Solanum tuberosum) plant. The current study carried out a genome-wide study of StMAPK and provided a deep insight using bioinformatics tools. In addition, the relative expression of StMAPKs was also assessed in different plant tissues. The similarity search results identified a total of 22 StMAPK genes in the potato genome. The sequence alignment also showed conserved motif TEY/TDY in most StMAPKs with conserved docking LHDXXEP sites. The phylogenetic analysis divided all 22 StMAPK genes into five groups, i.e., A, B, C, D, and E, showing some common structural motifs. In addition, most of the StMAPKs were found in a cluster form at the terminal of chromosomes. The promoter analysis predicted several stress-responsive Cis-acting regulatory elements in StMAPK genes. Gene duplication under selection pressure also indicated several purifying and positive selections in StMAPK genes. In potato, StMAPK2, StMAPK6, and StMAPK19 showed a high expression in response to heat stress. Under ABA and IAA treatment, the expression of the total 20 StMAPK genes revealed that ABA and IAA played an essential role in this defense process. The expression profiling and real-time qPCR (RT-qPCR) exhibited their high expression in roots and stems compared to leaves. These results deliver primary data for functional analysis and provide reference data for other important crops.

scholarly journals Puumala and Andes Orthohantaviruses Cause Transient Protein Kinase R-Dependent Formation of Stress Granules

2019 ◽  
Vol 94 (3) ◽  
Author(s):  
Wanda Christ ◽  
Janne Tynell ◽  
Jonas Klingström
Keyword(s):  
Protein Kinase ◽  
Host Cell ◽  
Stress Responses ◽  
Stress Granules ◽  
Cell Stress ◽  
Stress Granule ◽  
Hantavirus Infection ◽  
Stress Signaling ◽  
Protein Kinase R ◽  
Granule Formation

ABSTRACT Virus infection frequently triggers host cell stress signaling resulting in translational arrest; as a consequence, many viruses employ means to modulate the host stress response. Hantaviruses are negative-sense, single-stranded RNA viruses known to inhibit host innate immune responses and apoptosis, but their impact on host cell stress signaling remains largely unknown. In this study, we investigated activation of host cell stress responses during hantavirus infection. We show that hantavirus infection causes transient formation of stress granules (SGs) but does so in only a limited proportion of infected cells. Our data indicate some cell type-specific and hantavirus species-specific variability in SG prevalence and show SG formation to be dependent on the activation of protein kinase R (PKR). Hantavirus infection inhibited PKR-dependent SG formation, which could account for the transient nature and low prevalence of SG formation observed during hantavirus infection. In addition, we report only limited colocalization of hantaviral proteins or RNA with SGs and show evidence indicating hantavirus-mediated inhibition of PKR-like endoplasmic reticulum (ER) kinase (PERK). IMPORTANCE Our work presents the first report on stress granule formation during hantavirus infection. We show that hantavirus infection actively inhibits stress granule formation, thereby escaping the detrimental effects on global translation imposed by host stress signaling. Our results highlight a previously uncharacterized aspect of hantavirus-host interactions with possible implications for how hantaviruses are able to cause persistent infection in natural hosts and for pathogenesis.

scholarly journals Activation of a Novel Transcription Factor through Phosphorylation by WIPK, a Wound-Induced Mitogen-Activated Protein Kinase in Tobacco Plants

2005 ◽  
Vol 139 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Yun-Kiam Yap ◽  
Yutaka Kodama ◽  
Frank Waller ◽  
Kwi Mi Chung ◽  
Hirokazu Ueda ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Tobacco Plants ◽  
Mitogen Activated Protein

scholarly journals W55aEncodes a Novel Protein Kinase That Is Involved in Multiple Stress Responses

2009 ◽  
Vol 51 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Zhao-Shi Xu ◽  
Li Liu ◽  
Zhi-Yong Ni ◽  
Pei Liu ◽  
Ming Chen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Stress Responses ◽  
Multiple Stress ◽  
Novel Protein
Sign in / Sign up

Export Citation Format

Share Document