The protein kinase SlCIPK23 boosts K + and Na + uptake in tomato plants

Potassium Affects Sodium Content in Tomato Plants Grown in Hydroponic Cultivation under Saline-sodic Stress

HortScience ◽

10.21273/hortsci.35.7.1220 ◽

2000 ◽

Vol 35 (7) ◽

pp. 1220-1222 ◽

Cited By ~ 8

Author(s):

L. Botrini ◽

A. Graifenberg ◽

M. Lipucci di Paola

Keyword(s):

Electrical Conductivity ◽

Lycopersicon Esculentum ◽

High Salinity ◽

Dry Weight ◽

Sodium Content ◽

Fresh Weight ◽

Tomato Plants ◽

Hydroponic Cultivation ◽

Tomato Cultivars ◽

Na Uptake

The tomato cultivars Edkawi and UC 82B (Lycopersicon esculentum Mill.) were grown hydroponically in a solution [electrical conductivity (EC) 2.4 dS·m-1] containing 150 mm Na (EC 11.4 dS·m-1), 37 mm of K (EC 14.1 dS·m-1), or 75 mm of K (EC 19.7 dS·m-1). The leaf Na content of `Edkawi' and `UC 82B' reached values of 1717 and 2022 mmol·kg-1 dry weight at EC 19.7 dS·m-1, respectively. The high levels of K in the hydroponic solution reduced the Na concentration in the roots, petioles, and stems, but not in the leaves. Potassium concentrations in the petioles of `Edkawi' and `UC 82 B' reached values of 2655 and 2966 mmol·kg-1 dry weight, respectively. At these elevated ECs, the Ca concentrations in the leaves of `Edkawi' and `UC 82B' were 30% and 40% lower than in the control, respectively. The elevated rates of K improved the fruit: flower ratio of `UC 82B', but the high salinity of the solution reduced yields significantly. Plant fresh weight and root dry weight of `UC 82B' were most affected by high EC levels. The elevated levels of K used in this study did not increase yield, but K ions can adjust to Na uptake.

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Phorbol ester inhibition of chicken intestinal brush-border sodium-proton exchange

AJP Cell Physiology ◽

10.1152/ajpcell.1991.260.6.c1264 ◽

1991 ◽

Vol 260 (6) ◽

pp. C1264-C1272 ◽

Cited By ~ 11

Author(s):

E. B. Chang ◽

M. W. Musch ◽

D. Drabik-Arvans ◽

M. C. Rao

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Phorbol Ester ◽

Brush Border ◽

Time Course ◽

Brush Border Membrane ◽

Phorbol Esters ◽

Kinase C ◽

Na Uptake ◽

Exchange Activity

Phorbol esters, specific activators of protein kinase C, inhibit amiloride-sensitive Na uptake from the mucosal medium in intact intestinal mucosa as well as in isolated chicken villus enterocytes. In isolated cells, maximal inhibition is observed at 60 s, and influx returns to control values within 15 min. This effect can be measured either as initial 22Na influx rates or by following changes in intracellular pH using the pH-sensitive fluorescent dye 5,6-carboxyfluorescein. The effects of amiloride and phorbol esters were not additive, suggesting inhibition of a common transport system, i.e., Na-H exchange. In brush-border membrane vesicles (BBMV) made from villus enterocytes, amiloride-sensitive Na-H exchange activity was significantly inhibited in phorbol ester-treated cells. The degree of inhibition of 22Na uptake by BBMV had the same time course and dose-effect relationship as phorbol ester-inhibited cellular Na uptake. Similarly, the time course of protein kinase C translocation from cytosol to particulate or brush-border membrane fractions correlated with Na uptake measurements made in whole cells and BBMV. These results suggest that protein kinase C activation in chicken villus enterocytes inhibits brush-border membrane Na-H exchange activity.

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α1-Adrenergic receptors activate NHE1 and NHE3 through distinct signaling pathways in epithelial cells

AJP Renal Physiology ◽

10.1152/ajprenal.2001.280.3.f415 ◽

2001 ◽

Vol 280 (3) ◽

pp. F415-F425 ◽

Cited By ~ 26

Author(s):

Fengming Liu ◽

Frank A. Gesek

Keyword(s):

Protein Kinase ◽

Epithelial Cells ◽

Protein Expression ◽

Signaling Pathways ◽

Intracellular Ph ◽

Adrenergic Receptors ◽

Mitogen Activated Protein Kinase ◽

Mitogen Activated Protein ◽

Nhe Isoforms ◽

Na Uptake

The Na+/H+ exchanger (NHE) regulates intracellular pH, cell volume, Na+ absorption and H+secretion in epithelial cells of the renal proximal tubule (PT). α1-Adrenergic receptors (ARs) increase NHE activity in PT cells. The purpose of this study was to determine the mechanism of α1-AR activation of NHE isoforms expressed in PT cells. Northern and Western blotting demonstrate transcripts and protein expression of NHE1 and NHE3 in PT cells. An anti-NHE1 antibody predominately labels protein expressed at basal and lateral membranes. In contrast, NHE3 protein is expressed exclusively at the apical membrane. To determine NHE isoforms regulated by α1-ARs, antisense oligodeoxynucleotides (AS-ODNs) specific for NHE1 and NHE3 isoforms were introduced into cells with streptolysin O permeabilization. Cells incubated with AS-ODNs a total of three times exhibited a reduction in protein expression of ∼85%. Na uptake and changes in intracellular pH (pHi) were used as measures of NHE activity in PT cells. α1-AR stimulation increased Na uptake from 8.5 to 13.8 nmol · min−1 · mg protein−1. AS-ODNs to NHE3 significantly reduced α1-AR stimulated Na uptake and increases in pHi; no effect was observed in sense-ODN-treated cells. Inhibition of NHE1 but not NHE3 expression abolishes amiloride-suppressible NHE activity. α1-AR stimulation of NHE1 is inhibited by the protein kinase C (PKC) inhibitor calphostin C whereas NHE3 activity is abolished by the mitogen-activated protein kinase (MAPK) inhibitor PD-98059. In PT cells transfected with MAPK kinase MEKK1COOH, a truncated version of MEKK1 that activates MAPK, NHE3 but not NHE1 activity is stimulated. We conclude that α1-ARs activate distinct signaling pathways to regulate specific NHE isoforms localized on opposite membranes in polarized renal epithelial cells. α1-AR activation of NHE1 is regulated by PKC whereas NHE3 is controlled by MAPK and serves to separately regulate pHi, Na absorption, and proton excretion in PT cells.

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A Calcium-Dependent Protein Kinase Is Systemically Induced upon Wounding in Tomato Plants

PLANT PHYSIOLOGY ◽

10.1104/pp.010649 ◽

2002 ◽

Vol 128 (1) ◽

pp. 256-270 ◽

Cited By ~ 78

Author(s):

José Manuel Chico ◽

Marcela Raı́ces ◽

Marı́a Teresa Téllez-Iñón ◽

Rita Marı́a Ulloa

Keyword(s):

Protein Kinase ◽

Dependent Protein Kinase ◽

Tomato Plants ◽

Calcium Dependent ◽

Dependent Protein ◽

Calcium Dependent Protein Kinase

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Inhibition of epithelial Na+ transport by atriopeptin, protein kinase c, and pertussis toxin

AJP Renal Physiology ◽

10.1152/ajprenal.1987.253.2.f372 ◽

1987 ◽

Vol 253 (2) ◽

pp. F372-F376 ◽

Cited By ~ 3

Author(s):

M. Mohrmann ◽

H. F. Cantiello ◽

D. A. Ausiello

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Regulatory Protein ◽

Guanine Nucleotide ◽

Kinase C ◽

Guanine Nucleotide Regulatory Protein ◽

Na Uptake ◽

Atrial Natriuretic

We have recently shown the selective inhibition of an amiloride-sensitive, conductive pathway for Na+ by atrial natriuretic peptide and 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP) in the renal epithelial cell line, LLC-PK1. Using 22Na+ fluxes, we further investigated the modulation of Na+ transport by atrial natriuretic peptide and by agents that increase cGMP production, activate protein kinase c, or modulate guanine nucleotide regulatory protein function. Sodium nitroprusside increases intracellular cGMP concentrations without affecting cAMP concentrations and completely inhibits amiloride-sensitive Na+ uptake in a time- and concentration-dependent manner. In contrast, 8-BrcAMP is without effect on Na+ uptake through the Na+ channel. 1-Oleoyl 2-acetylglycerol (10 micrograms/ml) and phorbol 12-myristate 13-acetate (100 nM), activators of protein kinase c, inhibit Na+ uptake by 93 +/- 13 and 51 +/- 10%, respectively. Prolonged incubation with phorbol ester results in the downregulation of protein kinase c activity and reduces the inhibitory effect of atrial natriuretic peptide, suggesting that the action of this peptide involves stimulation of protein kinase c. Pertussis toxin, which induces the ADP-ribosylation of a 41-kDa guanine nucleotide regulatory protein in LLC-PK1 cells, inhibits 22Na+ influx to the same extent as amiloride. Thus, increasing cGMP, activating protein kinase c, and ADP-ribosylating a guanine nucleotide regulatory protein all inhibit Na+ uptake. These events may be sequentially involved in the action of atrial natriuretic peptide.

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A role for the actin cytoskeleton in the hormonal and growth-factor-mediated activation of protein kinase B

Biochemical Journal ◽

10.1042/0264-6021:3530735v ◽

2001 ◽

Vol 353 (3) ◽

pp. 735

Author(s):

K. PEYROLLIER ◽

E. HAJDUCH ◽

A. GRAY ◽

G. J. LITHERLAND ◽

A. R. PRESCOTT ◽

...

Keyword(s):

Growth Factor ◽

Protein Kinase ◽

Actin Cytoskeleton ◽

Protein Kinase B

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Early signalling events of autophagy

Essays in Biochemistry ◽

10.1042/bse0550001 ◽

2013 ◽

Vol 55 ◽

pp. 1-15 ◽

Cited By ~ 16

Author(s):

Laura E. Gallagher ◽

Edmond Y.W. Chan

Keyword(s):

Protein Kinase ◽

Focal Adhesion Kinase ◽

Focal Adhesion ◽

Mammalian Cells ◽

Mammalian Target Of Rapamycin ◽

Interacting Protein ◽

The Core ◽

Autophagy Gene ◽

Autophagy Induction ◽

Cellular Pathways

Autophagy is a conserved cellular degradative process important for cellular homoeostasis and survival. An early committal step during the initiation of autophagy requires the actions of a protein kinase called ATG1 (autophagy gene 1). In mammalian cells, ATG1 is represented by ULK1 (uncoordinated-51-like kinase 1), which relies on its essential regulatory cofactors mATG13, FIP200 (focal adhesion kinase family-interacting protein 200 kDa) and ATG101. Much evidence indicates that mTORC1 [mechanistic (also known as mammalian) target of rapamycin complex 1] signals downstream to the ULK1 complex to negatively regulate autophagy. In this chapter, we discuss our understanding on how the mTORC1–ULK1 signalling axis drives the initial steps of autophagy induction. We conclude with a summary of our growing appreciation of the additional cellular pathways that interconnect with the core mTORC1–ULK1 signalling module.

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Spatial control of actin-based motility through plasmalemmal PtdIns(4,5)P2-rich raft assemblies.

Biochemical Society Symposium ◽

10.1042/bss0720119 ◽

2005 ◽

Vol 72 ◽

pp. 119-127 ◽

Cited By ~ 19

Author(s):

Tamara Golub ◽

Caroni Pico

Keyword(s):

Protein Kinase ◽

Cell Surface ◽

Actin Cytoskeleton ◽

Lipid Rafts ◽

Patch Clustering ◽

Pkc Protein Kinase C ◽

Membrane Bound ◽

And Function ◽

Cytoskeleton Dynamics ◽

Syndrome Protein

The interactions of cells with their environment involve regulated actin-based motility at defined positions along the cell surface. Sphingolipid- and cholesterol-dependent microdomains (rafts) order proteins at biological membranes, and have been implicated in most signalling processes at the cell surface. Many membrane-bound components that regulate actin cytoskeleton dynamics and cell-surface motility associate with PtdIns(4,5)P2-rich lipid rafts. Although raft integrity is not required for substrate-directed cell spreading, or to initiate signalling for motility, it is a prerequisite for sustained and organized motility. Plasmalemmal rafts redistribute rapidly in response to signals, triggering motility. This process involves the removal of rafts from sites that are not interacting with the substrate, apparently through endocytosis, and a local accumulation at sites of integrin-mediated substrate interactions. PtdIns(4,5)P2-rich lipid rafts can assemble into patches in a process depending on PtdIns(4,5)P2, Cdc42 (cell-division control 42), N-WASP (neural Wiskott-Aldrich syndrome protein) and actin cytoskeleton dynamics. The raft patches are sites of signal-induced actin assembly, and their accumulation locally promotes sustained motility. The patches capture microtubules, which promote patch clustering through PKA (protein kinase A), to steer motility. Raft accumulation at the cell surface, and its coupling to motility are influenced greatly by the expression of intrinsic raft-associated components that associate with the cytosolic leaflet of lipid rafts. Among them, GAP43 (growth-associated protein 43)-like proteins interact with PtdIns(4,5)P2 in a Ca2+/calmodulin and PKC (protein kinase C)-regulated manner, and function as intrinsic determinants of motility and anatomical plasticity. Plasmalemmal PtdIns(4,5)P2-rich raft assemblies thus provide powerful organizational principles for tight spatial and temporal control of signalling in motility.

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