scholarly journals Stimulus-specific processing of the plasma membrane receptor-like kinase FERONIA in Arabidopsis thaliana

2021 ◽  
Author(s):  
Gabriele B Monshausen ◽  
Cassidy S Cornblatt ◽  
Han-Wei Shih
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
Mechanical Stimulation ◽  
Cysteine Protease ◽  
Plant Immunity ◽  
Response To Treatment ◽  
Peptide Ligand ◽  
Mechanical Wounding ◽  
Independent Manner ◽  
Receptor Like Kinase

FERONIA (FER), a receptor-like kinase involved in plant immunity, cell expansion, and mechanical signal transduction, is known to be endocytosed and degraded in response to treatment with its peptide ligand RAPID ALKALINIZATION FACTOR 1 (RALF1). Using confocal fluorescence microscopy and biochemical assays, we have found that full length FER-eGFP abundance at the plasma membrane is also regulated by mechanical stimulation, but through a separate, cysteine protease-dependent pathway. Like RALF1 treatment, both mechanical bending and mechanical wounding trigger a reduction in plasma membrane-localized, native promoter-driven FER-eGFP in Arabidopsis roots, hypocotyls, and cotyledons. However, pharmacological inhibition of protein trafficking and degradation suggests that while RALF1 induces clathrin-mediated endocytosis and subsequent degradation of FER-eGFP, mechanical stimulation triggers cleavage and/or degradation of FER-eGFP in a cysteine protease-dependent, clathrin-independent manner. Despite the stimulus-dependent differences in these two pathways, we found that both require early FER signaling components, including Ca2+ signaling, FER kinase activity, and the presence of LLG1, a FER-interacting protein with an essential role in FER-dependent signal transduction.

scholarly journals Structure of the Signal Transduction Domain in Second-Generation CAR Regulates the Input Efficiency of CAR Signals

2021 ◽  
Vol 22 (5) ◽  
pp. 2476
Author(s):  
Kento Fujiwara ◽  
Masaki Kitaura ◽  
Ayaka Tsunei ◽  
Hotaka Kusabuka ◽  
Erika Ogaki ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
Second Generation ◽  
Independent Manner ◽  
Cell Functions ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
The Impact

T cells that are genetically engineered to express chimeric antigen receptor (CAR) have a strong potential to eliminate tumor cells, yet the CAR-T cells may also induce severe side effects due to an excessive immune response. Although optimization of the CAR structure is expected to improve the efficacy and toxicity of CAR-T cells, the relationship between CAR structure and CAR-T cell functions remains unclear. Here, we constructed second-generation CARs incorporating a signal transduction domain (STD) derived from CD3ζ and a 2nd STD derived from CD28, CD278, CD27, CD134, or CD137, and investigated the impact of the STD structure and signaling on CAR-T cell functions. Cytokine secretion of CAR-T cells was enhanced by 2nd STD signaling. T cells expressing CAR with CD278-STD or CD137-STD proliferated in an antigen-independent manner by their STD tonic signaling. CAR-T cells incorporating CD28-STD or CD278-STD between TMD and CD3ζ-STD showed higher cytotoxicity than first-generation CAR or second-generation CARs with other 2nd STDs. The potent cytotoxicity of these CAR-T cells was not affected by inhibiting the 2nd STD signals, but was eliminated by placing the STDs after the CD3ζ-STD. Our data highlighted that CAR activity was affected by STD structure as well as by 2nd STD signaling.

Mechanical signal transduction in skeletal muscle growth and adaptation

2005 ◽  
Vol 98 (5) ◽  
pp. 1900-1908 ◽  
Author(s):  
James G. Tidball
Keyword(s):  
Skeletal Muscle ◽  
Signal Transduction ◽  
Mechanical Activation ◽  
Signaling Pathways ◽  
Mechanical Stimulation ◽  
Muscle Growth ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Mechanical Signal ◽  
Igf I

The adaptability of skeletal muscle to changes in the mechanical environment has been well characterized at the tissue and system levels, but the mechanisms through which mechanical signals are transduced to chemical signals that influence muscle growth and metabolism remain largely unidentified. However, several findings have suggested that mechanical signal transduction in muscle may occur through signaling pathways that are shared with insulin-like growth factor (IGF)-I. The involvement of IGF-I-mediated signaling for mechanical signal transduction in muscle was originally suggested by the observations that muscle releases IGF-I on mechanical stimulation, that IGF-I is a potent agent for promoting muscle growth and affecting phenotype, and that IGF-I can function as an autocrine hormone in muscle. Accumulating evidence shows that at least two signaling pathways downstream of IGF-I binding can influence muscle growth and adaptation. Signaling via the calcineurin/nuclear factor of activated T-cell pathway has been shown to have a powerful influence on promoting the slow/type I phenotype in muscle but can also increase muscle mass. Neural stimulation of muscle can activate this pathway, although whether neural activation of the pathway can occur independent of mechanical activation or independent of IGF-I-mediated signaling remains to be explored. Signaling via the Akt/mammalian target of rapamycin pathway can also increase muscle growth, and recent findings show that activation of this pathway can occur as a response to mechanical stimulation applied directly to muscle cells, independent of signals derived from other cells. In addition, mechanical activation of mammalian target of rapamycin, Akt, and other downstream signals is apparently independent of autocrine factors, which suggests that activation of the mechanical pathway occurs independent of muscle-mediated IGF-I release.

scholarly journals A hydrophobic site on the GLP-1 receptor extracellular domain orients the peptide ligand for signal transduction

2013 ◽  
Vol 2 (2) ◽  
pp. 86-91 ◽  
Author(s):  
James T. Patterson ◽  
Pengyun Li ◽  
Jonathan W. Day ◽  
Vasily M. Gelfanov ◽  
Richard D. DiMarchi
Keyword(s):  
Signal Transduction ◽  
Extracellular Domain ◽  
Peptide Ligand ◽  
Hydrophobic Site

ADP-ribose gates the fertilization channel in ascidian oocytes

1998 ◽  
Vol 275 (5) ◽  
pp. C1277-C1283 ◽  
Author(s):  
Martin Wilding ◽  
Gian Luigi Russo ◽  
Anthony Galione ◽  
Marcella Marino ◽  
Brian Dale
Keyword(s):  
Plasma Membrane ◽  
Ion Channel ◽  
Reversal Potential ◽  
Ciona Intestinalis ◽  
Second Messenger ◽  
Tetraacetic Acid ◽  
Independent Manner ◽  
Unitary Conductance ◽  
Intracellular Ca ◽  
Hydrolysis Of

We report an ion channel in the plasma membrane of unfertilized oocytes of the ascidian Ciona intestinalis that is directly gated by the second messenger ADP-ribose. The ion channel is permeable to Ca2+ and Na+ and is characterized by a reversal potential between 0 and +20 mV and a unitary conductance of 140 pS. Preinjection of the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid (BAPTA) or antagonists of intracellular Ca2+ release channels into oocytes did not inhibit the ADP-ribose current, demonstrating that the channel is activated in a Ca2+-independent manner. Both the fertilization current and the current induced by the injection of nicotinamide nucleotides are blocked by nicotinamide, suggesting that the ADP-ribose channel is activated at fertilization in a nicotinamide-sensitive manner. These data suggest that ascidian sperm trigger the hydrolysis of nicotinamide nucleotides in the oocyte to ADP-ribose and that this mechanism is responsible for the production of the fertilization current.

scholarly journals Tyrosine phosphorylation of the lectin receptor‐like kinase LORE regulates plant immunity

2020 ◽  
Vol 39 (4) ◽  
Author(s):  
Xuming Luo ◽  
Wei Wu ◽  
Yingbo Liang ◽  
Ning Xu ◽  
Zongyi Wang ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Plant Immunity ◽  
Lectin Receptor ◽  
Receptor Like Kinase

scholarly journals Morphological Alterations of CAD Cells Overexpressing AKT1

2020 ◽  
Vol 26 (S2) ◽  
pp. 1354-1358
Author(s):  
James Wachira
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
Cell Survival ◽  
Fluorescent Protein ◽  
Morphological Changes ◽  
Protein Localization ◽  
Signal Transduction Pathways ◽  
Morphological Alterations ◽  
Cellular Models ◽  
Cad Cells

AbstractCAD cells are neuronal cells used in studies of cell differentiation and in cellular models of neuropathology. When cultured in differentiation medium, CAD cells exhibit characteristics of mature neurons including the generation of action potential. In addition to being a central signaling kinase in cell survival, AKT1 plays important roles in the nervous system including neuroplasticity and this study examined the localization of exogenous AKT1 in CAD cells. Neuropeptides modulate many signal transduction pathways and melacortins are implicated in regulating growth factor signal transduction pathways, including the PI3K/AKT pathway. AKT1-DsReD was transfected into CAD cells that were stably expressing melanocortin 3-receptor-GFP (MC3R-GFP), a G-protein coupled receptor. The cells were imaged with confocal microscopy to determine the fluorescent protein localization patterns. AKT1-DsRed was predominantly localized in the cytoplasm and the nucleus. Further, expression of exogenous AKT1 in these cell lines led to morphological changes reminiscent of apoptosis. As expected, MC3R-GFP localized to the plasma membrane but it internalized upon cell stimulation with the cognate ligand. In limited areas of the plasma membrane, AKT1-DsRed and MC3R-GFP were colocalized. In conclusion, quantitative studies to understand the role of relative levels of AKT1 in determining cell survival are needed.

scholarly journals Fluorescent, short-chain C6-NBD-sphingomyelin, but not C6-NBD-glucosylceramide, is subject to extensive degradation in the plasma membrane: implications for signal transduction related to cell differentiation

1995 ◽  
Vol 309 (3) ◽  
pp. 905-912 ◽  
Author(s):  
J W Kok ◽  
T Babia ◽  
K Klappe ◽  
D Hoekstra
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
Cell Differentiation ◽  
Plasma Membranes ◽  
Cell Types ◽  
Short Chain ◽  
Synthetic Activity ◽  
Intact Cells ◽  
Ht29 Cells ◽  
Extensive Degradation

The involvement of the plasma membrane in the metabolism of the sphingolipids sphingomyelin (SM) and glucosylceramide (GlcCer) was studied, employing fluorescent short-chain analogues of these lipids, 6-[N-(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]hexanoylsphingosylphosphorylcholine (C6-NBD-SM), C6-NBD-GlcCer and their common biosynthetic precursor C6-NBD-ceramide (C6-NBD-Cer). Although these fluorescent short-chain analogues are metabolically active, some caution is to be taken in view of potential changes in biophysical/biochemical properties of the lipid compared with its natural counterpart. However, these short-chain analogues offer the advantage of studying the lipid metabolic enzymes in their natural environment, since detergent solubilization is not necessary for measuring their activity. These studies were carried out with several cell types, including two phenotypes (differing in state of differentiation) of HT29 cells. Degradation and biosynthesis of C6-NBD-SM and C6-NBD-GlcCer were determined in intact cells, in their isolated plasma membranes, and in plasma membranes isolated from rat liver tissue. C6-NBD-SM was found to be subject to extensive degradation in the plasma membrane, due to neutral sphingomyelinase (N-SMase) activity. The extent of C6-NBD-SM hydrolysis showed a general cell-type dependence and turned out to be dependent on the state of cell differentiation, as revealed for HT29 cells. In undifferentiated HT29 cells N-SMase activity was at least threefold higher than in its differentiated counterpart. In contrast, in all cell types studied, very little if any biosynthesis of C6-NBD-SM from the precursor C6-NBD-Cer occurred. Moreover, in the case of C6-NBD-GlcCer, neither hydrolytic nor synthetic activity was found to be associated with the plasma membrane. These results are discussed in the context of the involvement of the sphingolipids SM and GlcCer in signal transduction pathways in the plasma membrane.

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