共查询到20条相似文献,搜索用时 93 毫秒
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Sukru S. Oner Ali Vural Stephen M. Lanier 《The Journal of biological chemistry》2013,288(33):24091-24103
Group II activators of G-protein signaling play diverse functional roles through their interaction with Gαi, Gαt, and Gαo via a G-protein regulatory (GPR) motif that serves as a docking site for Gα-GDP. We recently reported the regulation of the AGS3-Gαi signaling module by a cell surface, seven-transmembrane receptor. Upon receptor activation, AGS3 reversibly dissociates from the cell cortex, suggesting that it may function as a signal transducer with downstream signaling implications, and this question is addressed in the current report. In HEK-293 and COS-7 cells expressing the α2A/D-AR and Gαi3, receptor activation resulted in the translocation of endogenous AGS3 and AGS3-GFP from the cell cortex to a juxtanuclear region, where it co-localized with markers of the Golgi apparatus (GA). The agonist-induced translocation of AGS3 was reversed by the α2-AR antagonist rauwolscine. The TPR domain of AGS3 was required for agonist-induced translocation of AGS3 from the cell cortex to the GA, and the translocation was blocked by pertussis toxin pretreatment or by the phospholipase Cβ inhibitor . Agonist-induced translocation of AGS3 to the GA altered the functional organization and protein sorting at the trans-Golgi network. The regulated movement of AGS3 between the cell cortex and the GA offers unexpected mechanisms for modulating protein secretion and/or endosome recycling events at the trans-Golgi network. U73122相似文献
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A number of studies suggest that OLGs (oligodendrocytes), the myelinating cells of the central nervous system, are also a source of trophic molecules, such as neurotrophins that may influence survival of proximate neurons. What is less clear is how the release of these molecules may be regulated. The present study investigated the effects of BDNF (brain-derived neurotrophic factor) derived from cortical OLGs on proximate neurons, as well as regulatory mechanisms mediating BDNF release. Initial work determined that BDNF derived from cortical OLGs increased the numbers of VGLUT1 (vesicular glutamate transporter 1)-positive glutamatergic cortical neurons. Furthermore, glutamate acting through metabotropic, and not AMPA/kainate or NMDA (N-methyl-d-aspartate), receptors increased BDNF release. The PLC (phospholipase C) pathway is a key mediator of metabotropic actions to release BDNF in astrocytes and neurons. Treatment of OLGs with the PLC activator m-3M3FBS [N-(3-trifluoromethylphenyl)-2,4,6-trimethylbenzenesulfonamide] induced robust release of BDNF. Moreover, release elicited by the metabotropic receptor agonist ACPD [trans-(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid] was inhibited by the PLC antagonist , the IP3 (inositol triphosphate 3) receptor inhibitor 2-APB (2-aminoethoxydiphenylborane) and the intracellular calcium chelator BAPTA/AM [1,2-bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid tetrakis(acetoxymethyl ester)]. Taken together, these results suggest that OLG lineage cells release BDNF, a molecule trophic for proximate neurons. BDNF release is regulated by glutamate acting through mGluRs (metabotropic glutamate receptors) and the PLC pathway. Thus glutamate and BDNF may be molecules that support neuron–OLG interactions in the cortex. U73122相似文献
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Debabrata Laha Philipp Johnen Cristina Azevedo Marek Dynowski Michael Wei? Samanta Capolicchio Haibin Mao Tim Iven Merel Steenbergen Marc Freyer Philipp Gaugler Marília K.F. de Campos Ning Zheng Ivo Feussner Henning J. Jessen Saskia C.M. Van Wees Adolfo Saiardi Gabriel Schaaf 《The Plant cell》2015,27(4):1082-1097
Diphosphorylated inositol polyphosphates, also referred to as inositol pyrophosphates, are important signaling molecules that regulate critical cellular activities in many eukaryotic organisms, such as membrane trafficking, telomere maintenance, ribosome biogenesis, and apoptosis. In mammals and fungi, two distinct classes of inositol phosphate kinases mediate biosynthesis of inositol pyrophosphates: Kcs1/IP6K- and Vip1/PPIP5K-like proteins. Here, we report that PPIP5K homologs are widely distributed in plants and that Arabidopsis thaliana VIH1 and VIH2 are functional PPIP5K enzymes. We show a specific induction of inositol pyrophosphate InsP8 by jasmonate and demonstrate that steady state and jasmonate-induced pools of InsP8 in Arabidopsis seedlings depend on VIH2. We identify a role of VIH2 in regulating jasmonate perception and plant defenses against herbivorous insects and necrotrophic fungi. In silico docking experiments and radioligand binding-based reconstitution assays show high-affinity binding of inositol pyrophosphates to the F-box protein COI1-JAZ jasmonate coreceptor complex and suggest that coincidence detection of jasmonate and InsP8 by COI1-JAZ is a critical component in jasmonate-regulated defenses. 相似文献
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Patrice Meimoun Guillaume Vidal Anne-Sophie Bohrer Arnaud Lehner Daniel Tran Jo?l Briand Fran?ois Bouteau Jean-Pierre Rona 《Plant signaling & behavior》2009,4(9):830-835
In Arabidopsis thaliana cell suspension,abscisic acid (aBa) induces changes in cytosolic calcium concentration ([Ca2+]cyt) which are the trigger for aBa-induced plasma membrane anion current activation, H+-aTPase inhibition, and subsequent plasma membrane depolarization. In the present study, we took advantage of this model to analyze the implication of intracellular Ca2+ stores in aBa signal transduction through electrophysiological current measurements, cytosolic Ca2+ activity measurements with the apoaequorin Ca2+ reporter protein and external pH measurement. Intracellular Ca2+ stores involvement was determined by using specific inhibitors of CICR channels: the cADP-ribose/ryanodine receptor (Br-cADPR and dantrolene) and of the inositol trisphosphate receptor (). In addition experiments were performed on epidermal strips of A. thaliana leaves to monitor stomatal closure in response to ABA in presence of the same pharmacology. Our data provide evidence that ryanodine receptor and inositol trisphosphate receptor could be involved in ABA-induced (1) Ca2+ release in the cytosol, (2) anion channel activation and H+-ATPase inhibition leading to plasma membrane depolarization and (3) stomatal closure. Intracellular Ca2+ release could thus contribute to the control of early events in the ABA signal transduction pathway in A. thaliana. U73122相似文献
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Beate Fuchs Markus Rupp Hossein A Ghofrani Ralph T Schermuly Werner Seeger Friedrich Grimminger Thomas Gudermann Alexander Dietrich Norbert Weissmann 《Respiratory research》2011,12(1):20
Background
Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism of the lung that matches blood perfusion to alveolar ventilation to optimize gas exchange. Recently we have demonstrated that acute but not sustained HPV is critically dependent on the classical transient receptor potential 6 (TRPC6) channel. However, the mechanism of TRPC6 activation during acute HPV remains elusive. We hypothesize that a diacylglycerol (DAG)-dependent activation of TRPC6 regulates acute HPV.Methods
We investigated the effect of the DAG analog 1-oleoyl-2-acetyl-sn-glycerol (OAG) on normoxic vascular tone in isolated perfused and ventilated mouse lungs from TRPC6-deficient and wild-type mice. Moreover, the effects of OAG, the DAG kinase inhibitor and the phospholipase C inhibitor R59949 on the strength of HPV were investigated compared to those on non-hypoxia-induced vasoconstriction elicited by the thromboxane mimeticum U46619. U73122Results
OAG increased normoxic vascular tone in lungs from wild-type mice, but not in lungs from TRPC6-deficient mice. Under conditions of repetitive hypoxic ventilation, OAG as well as dose-dependently attenuated the strength of acute HPV whereas U46619-induced vasoconstrictions were not reduced. Like OAG, R59949 mimicked HPV, since it induced a dose-dependent vasoconstriction during normoxic ventilation. In contrast, R59949, a blocker of DAG synthesis, inhibited acute HPV whereas U73122, the inactive form of U73343, had no effect on HPV. U73122Conclusion
These findings support the conclusion that the TRPC6-dependency of acute HPV is induced via DAG. 相似文献8.
Susan F. Wood Ete Z. Szuts Alan Fein 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1990,160(3):293-298
Summary Inositol 1,4,5-trisphosphate (InsP3) is rapidly formed in squid photoreceptors in response to light, where it is converted sequenctially into inositol bisphosphate (InsP2) and inositol monophosphate (InsP1). All of the InsP3 appears to be degraded to inositol 1,4-bisphosphate via an InsP3-phosphatase, which is characterized in this study. The enzyme is water-soluble and present in the light-transducing distal segments of squid photoreceptors. It has a Km of 50 M for InsP3, requires Mg++ for its activity, is maximally active at neutral pH, specifically hydrolyses the 5-phosphate and is inhibited by 2,3-diphosphoglycerate. In these respects, InsP3-phosphatase of squid is very similar to the enzymes of other cells. Since no InsP4 or more highly phosphorylated inositols are found in squid photoreceptors, the InsP3-phosphatase may be important in the regulation of InsP3 concentration within these cells.Abbreviations
InsP
1
, InsP
2
, InsP
3
, InsP
4
, InsP
6
inositol monobis-, tris-, tetrakis-, hexakisphosphate, respectively
-
2,3-DPG
2,3-diphosphoglycerate
-
EDTA
ethylene diamine tetraacetic acid
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DTT
dithiothreitol
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Hepes
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
-
PMSF
phenylmethylsulfonyl fluoride 相似文献
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Tae Hoon Kwon Hyunwoo Jung Eun Jeong Cho Ji Hoon Jeong Uy Dong Sohn 《Molecules and cells》2015,38(7):616-623
P2 receptors are membrane-bound receptors for extracellular nucleotides such as ATP and UTP. P2 receptors have been classified as ligand-gated ion channels or P2X receptors and G protein-coupled P2Y receptors. Recently, purinergic signaling has begun to attract attention as a potential therapeutic target for a variety of diseases especially associated with gastroenterology. This study determined the ATP and UTP-induced receptor signaling mechanism in feline esophageal contraction. Contraction of dispersed feline esophageal smooth muscle cells was measured by scanning micrometry. Phosphorylation of MLC20 was determined by western blot analysis. ATP and UTP elicited maximum esophageal contraction at 30 s and 10 μM concentration. Contraction of dispersed cells treated with 10 μM ATP was inhibited by nifedipine. However, contraction induced by 0.1 μM ATP, 0.1 μM UTP and 10 μM UTP was decreased by , chelerythrine, ML-9, PTX and GDPβS. Contraction induced by 0.1 μM ATP and UTP was inhibited by Gαi3 or Gαq antibodies and by PLCβ1 or PLCβ3 antibodies. Phosphorylated MLC20 was increased by ATP and UTP treatment. In conclusion, esophageal contraction induced by ATP and UTP was preferentially mediated by P2Y receptors coupled to Gαi3 and G q proteins, which activate PLCβ1 and PLCβ3. Subsequently, increased intracellular Ca2+ and activated PKC triggered stimulation of MLC kinase and inhibition of MLC phosphatase. Finally, increased pMLC20 generated esophageal contraction. U73122相似文献
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Kazi Mirajul Hoque Owen M. Woodward Damian B. van Rossum Nicholas C. Zachos Linxi Chen George P.H. Leung William B. Guggino Sandra E. Guggino Chung-Ming Tse 《The Journal of general physiology》2010,135(1):43-58
Intestinal Cl− secretion is stimulated by cyclic AMP (cAMP) and intracellular calcium ([Ca2+]i). Recent studies show that protein kinase A (PKA) and the exchange protein directly activated by cAMP (Epac) are downstream targets of cAMP. Therefore, we tested whether both PKA and Epac are involved in forskolin (FSK)/cAMP-stimulated Cl− secretion. Human intestinal T84 cells and mouse small intestine were used for short circuit current (Isc) measurement in response to agonist-stimulated Cl− secretion. FSK-stimulated Cl− secretion was completely inhibited by the additive effects of the PKA inhibitor, H89 (1 µM), and the [Ca2+]i chelator, 1,2-bis-(o-aminophenoxy)-ethane-N,N,N’,N’-tetraacetic acid, tetraacetoxymethyl ester (BAPTA-AM; 25 µM). Both FSK and the Epac activator 8-pCPT-2’-O-Me-cAMP (50 µM) elevated [Ca2+]i, activated Ras-related protein 2, and induced Cl− secretion in intact or basolateral membrane–permeabilized T84 cells and mouse ileal sheets. The effects of 8-pCPT-2’-O-Me-cAMP were completely abolished by BAPTA-AM, but not by H89. In contrast, T84 cells with silenced Epac1 had a reduced Isc response to FSK, and this response was completely inhibited by H89, but not by the phospholipase C inhibitor or BAPTA-AM. The stimulatory effect of 8-pCPT-2’-O-Me-cAMP on Cl− secretion was not abolished by cystic fibrosis transmembrane conductance (CFTR) inhibitor 172 or glibenclamide, suggesting that CFTR channels are not involved. This was confirmed by lack of effect of 8-pCPT-2’-O-Me-cAMP on whole cell patch clamp recordings of CFTR currents in Chinese hamster ovary cells transiently expressing the human CFTR channel. Furthermore, biophysical characterization of the Epac1-dependent Cl− conductance of T84 cells mounted in Ussing chambers suggested that this conductance was hyperpolarization activated, inwardly rectifying, and displayed a Cl−>Br−>I− permeability sequence. These results led us to conclude that the Epac-Rap-PLC-[Ca2+]i signaling pathway is involved in cAMP-stimulated Cl− secretion, which is carried by a novel, previously undescribed Cl− channel. U73122相似文献
11.
《The Journal of cell biology》1994,127(3):847-857
We recently have demonstrated that EGF receptor (EGFR)-induced cell motility requires receptor kinase activity and autophosphorylation (P. Chen, K. Gupta, and A. Wells. 1994. J. Cell Biol. 124:547-555). This suggests that the immediate downstream effector molecule contains a src homology-2 domain. Phospholipase C gamma (PLC gamma) is among the candidate transducers of this signal because of its potential roles in modulating cytoskeletal dynamics. We utilized signaling-restricted EGFR mutants expressed in receptor devoid NR6 cells to determine if PLC activation is necessary for EGFR-mediated cell movement. Exposure to EGF (25 nM) augmented PLC activity in all five EGFR mutant cell lines which also responded by increased cell movement. Basal phosphoinositide turnover was not affected by EGF in the lines which do not present the enhanced motility response. The correlation between EGFR-mediated cell motility and PLC activity suggested, but did not prove, a causal link. A specific inhibitor of PLC, (1 microM) diminished both the EGF- induced motility and PLC responses, while its inactive analogue U73122 had no effect on these responses. Both the PLC and motility responses were decreased by expression of a dominant-negative PLC gamma-1 fragment in EGF-responsive infectant lines. Lastly, anti-sense oligonucleotides (20 microM) to PLC gamma-1 reduced both responses in NR6 cells expressing wild-type EGFR. These findings strongly support PLC gamma as the immediate post receptor effector in this motogenic pathway. We have demonstrated previously that EGFR-mediated cell motility and mitogenic signaling pathways are separable. The point of divergence is undefined. All kinase-active EGFR mutants induced the mitogenic response while only those which are autophosphorylated induced PLC activity. U73343 did not affect EGF-induced thymidine incorporation in these motility-responsive infectant cell lines. In addition, the dominant-negative PLC gamma-1 fragment did not diminish EGF-induced thymidine incorporation. All kinase active EGFR stimulated mitogen-activated protein (MAP) kinase activity, regardless of whether the receptors induced cell movement; this EGF-induced MAP kinase activity was not affected by U73122 at concentrations that depressed the motility response. Thus, the signaling pathways which lead to motility and cell proliferation diverge at the immediate post-receptor stage, and we suggest that this is accomplished by differential activation of effector molecules. U73122相似文献
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Joshua T. Maxwell Sankar Natesan Gregory A. Mignery 《The Journal of biological chemistry》2012,287(47):39419-39428
InsP3-mediated calcium release through the type 2 inositol 1,4,5-trisphosphate receptor (InsP3R2) in cardiac myocytes results in the activation of associated CaMKII, thus enabling the kinase to act on downstream targets, such as histone deacetylases 4 and 5 (HDAC4 and HDAC5). The CaMKII activity also feedback modulates InsP3R2 function by direct phosphorylation and results in a dramatic decrease in the receptor-channel open probability (Po). We have identified S150 in the InsP3R2 core suppressor domain (amino acids 1–225) as the specific residue that is phosphorylated by CaMKII. Site-directed mutagenesis reveals that S150 is the CaMKII phosphorylation site responsible for modulation of channel activity. Nonphosphorylatable (S150A) and phosphomimetic (S150E) mutations were studied in planar lipid bilayers. The InsP3R2 S150A channel showed no decrease in activity when treated with CaMKII. Conversely, the phosphomimetic (S150E) channel displayed a very low Po under normal recording conditions in the absence of CaMKII (2 μm InsP3 and 250 nm [Ca2+]FREE) and mimicked a WT channel that has been phosphorylated by CaMKII. Phopho-specific antibodies demonstrate that InsP3R2 Ser-150 is phosphorylated in vivo by CaMKIIδ. The results of this study show that serine 150 of the InsP3R2 is phosphorylated by CaMKII and results in a decrease in the channel open probability. 相似文献
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Caglayan E Romeo GR Kappert K Odenthal M Südkamp M Body SC Shernan SK Hackbusch D Vantler M Kazlauskas A Rosenkranz S 《PloS one》2010,5(10):e13608
Background
Profilin-1 is an ubiquitous actin binding protein. Under pathological conditions such as diabetes, profilin-1 levels are increased in the vascular endothelium. We recently demonstrated that profilin-1 overexpression triggers indicators of endothelial dysfunction downstream of LDL signaling, and that attenuated expression of profilin-1 confers protection from atherosclerosis in vivo.Methodology
Here we monitored profilin-1 expression in human atherosclerotic plaques by immunofluorescent staining. The effects of recombinant profilin-1 on atherogenic signaling pathways and cellular responses such as DNA synthesis (BrdU-incorporation) and chemotaxis (modified Boyden-chamber) were evaluated in cultured rat aortic and human coronary vascular smooth muscle cells (VSMCs). Furthermore, the correlation between profilin-1 serum levels and the degree of atherosclerosis was assessed in humans.Principal Findings
In coronary arteries from patients with coronary heart disease, we found markedly enhanced profilin expression in atherosclerotic plaques compared to the normal vessel wall. Stimulation of rat aortic and human coronary VSMCs with recombinant profilin-1 (10−6 M) in vitro led to activation of intracellular signaling cascades such as phosphorylation of Erk1/2, p70S6 kinase and PI3K/Akt within 10 minutes. Furthermore, profilin-1 concentration-dependently induced DNA-synthesis and migration of both rat and human VSMCs, respectively. Inhibition of PI3K (Wortmannin, ) or Src-family kinases (SU6656, PP2), but not PLCγ ( LY294002), completely abolished profilin-induced cell cycle progression, whereas PI3K inhibition partially reduced the chemotactic response. Finally, we found that profilin-1 serum levels were significantly elevated in patients with severe atherosclerosis in humans (p<0.001 vs. no atherosclerosis or control group). U73122Conclusions
Profilin-1 expression is significantly enhanced in human atherosclerotic plaques compared to the normal vessel wall, and the serum levels of profilin-1 correlate with the degree of atherosclerosis in humans. The atherogenic effects exerted by profilin-1 on VSMCs suggest an auto-/paracrine role within the plaque. These data indicate that profilin-1 might critically contribute to atherogenesis and may represent a novel therapeutic target. 相似文献15.
Mi-Hye Lee Samar M. Hammad Andrea J. Semler Louis M. Luttrell Maria F. Lopes-Virella Richard L. Klein 《Journal of lipid research》2010,51(9):2619-2628
Sphingosine-1-phosphate (S1P) is a bioactive lysophospholipid that regulates numerous key cardiovascular functions. High-density lipoproteins (HDLs) are the major plasma lipoprotein carriers of S1P. Fibrinolysis is a physiological process that allows fibrin clot dissolution, and decreased fibrinolytic capacity may result from increased circulating levels of plasminogen activator inhibitor-1 (PAI-1). We examined the effect of S1P associated with HDL subfractions on PAI-1 secretion from 3T3 adipocytes. S1P concentration in HDL3 averaged twice that in HDL2. Incubation of adipocytes with increasing concentrations of S1P in HDL3, but not HDL2, or with S1P complexed to albumin stimulated PAI-I secretion in a concentration-dependent manner. Quantitative RT-PCR revealed that S1P1–3 are expressed in 3T3 adipocytes, with S1P2 expressed in the greatest amount. Treatment of adipocytes with the S1P1 and S1P3 antagonist VPC23019 did not block PAI-1 secretion. Inhibiting S1P2 with JTE-013 or reducing the expression of the gene coding for S1P2 using silencing RNA (siRNA) technology blocked PAI-1 secretion, suggesting that the S1P2 receptor mediates PAI-1 secretion from adipocytes exposed to HDL3 or S1P. Treatment with the phospholipase C (PLC) inhibitor , the protein kinase C (PKC) inhibitor RO-318425, or the Rho-associated protein kinase (ROCK) inhibitor Y27632 all significantly inhibited HDL3- and S1P-mediated PAI-1 release, suggesting that HDL3- and/or S1P-stimulated PAI-1 secretion from 3T3 cells is mediated by activation of multiple, downstream signaling pathways of S1P2. U73122相似文献
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Fen Hu Leiting Pan Kai Zhang Fulin Xing Xinyu Wang Imshik Lee Xinzheng Zhang Jingjun Xu 《PloS one》2014,9(9)
Aims
The local concentration of extracellular Ca2+ ([Ca2+]o) in bone microenvironment is accumulated during bone remodeling. In the present study we investigated whether elevating [Ca2+]o induced store-operated calcium entry (SOCE) in primary rat calvarial osteoblasts and further examined the contribution of elevating [Ca2+]o to osteoblastic proliferation.Methods
Cytosolic Ca2+ concentration ([Ca2+]c) of primary cultured rat osteoblasts was detected by fluorescence imaging using calcium-sensitive probe fura-2/AM. Osteoblastic proliferation was estimated by cell counting, MTS assay and ATP assay. Agonists and antagonists of calcium-sensing receptors (CaSR) as well as inhibitors of phospholipase C (PLC), SOCE and voltage-gated calcium (Cav) channels were applied to study the mechanism in detail.Results
Our data showed that elevating [Ca2+]o evoked a sustained increase of [Ca2+]c in a dose-dependent manner. This [Ca2+]c increase was blocked by TMB-8 (Ca2+ release inhibitor), 2-APB and BTP-2 (both SOCE blockers), respectively, whereas not affected by Cav channels blockers nifedipine and verapamil. Furthermore, NPS2143 (a CaSR antagonist) or (a PLC inhibitor) strongly reduced the [Ca2+]o-induced [Ca2+]c increase. The similar responses were observed when cells were stimulated with CaSR agonist spermine. These data indicated that elevating [Ca2+]o resulted in SOCE depending on the activation of CaSR and PLC in osteoblasts. In addition, high [Ca2+]o significantly promoted osteoblastic proliferation, which was notably reversed by BAPTA-AM (an intracellular calcium chelator), 2-APB, BTP-2, TMB-8, NPS2143 and U73122, respectively, but not affected by Cav channels antagonists. U73122Conclusions
Elevating [Ca2+]o induced SOCE by triggering the activation of CaSR and PLC. This process was involved in osteoblastic proliferation induced by high level of extracellular Ca2+ concentration. 相似文献18.
Mintu Desai Padma Rangarajan Janet L. Donahue Sarah P. Williams Eric S. Land Mihir K. Mandal Brian Q. Phillippy Imara Y. Perera Victor Raboy Glenda E. Gillaspy 《The Plant journal : for cell and molecular biology》2014,80(4):642-653
Inositol pyrophosphates are unique cellular signaling molecules with recently discovered roles in energy sensing and metabolism. Studies in eukaryotes have revealed that these compounds have a rapid turnover, and thus only small amounts accumulate. Inositol pyrophosphates have not been the subject of investigation in plants even though seeds produce large amounts of their precursor, myo‐inositol hexakisphosphate (InsP6). Here, we report that Arabidopsis and maize InsP6 transporter mutants have elevated levels of inositol pyrophosphates in their seed, providing unequivocal identification of their presence in plant tissues. We also show that plant seeds store a little over 1% of their inositol phosphate pool as InsP7 and InsP8. Many tissues, including, seed, seedlings, roots and leaves accumulate InsP7 and InsP8, thus synthesis is not confined to tissues with high InsP6. We have identified two highly similar Arabidopsis genes, AtVip1 and AtVip2, which are orthologous to the yeast and mammalian VIP kinases. Both AtVip1 and AtVip2 encode proteins capable of restoring InsP7 synthesis in yeast mutants, thus AtVip1 and AtVip2 can function as bonafide InsP6 kinases. AtVip1 and AtVip2 are differentially expressed in plant tissues, suggesting non‐redundant or non‐overlapping functions in plants. These results contribute to our knowledge of inositol phosphate metabolism and will lay a foundation for understanding the role of InsP7 and InsP8 in plants. 相似文献
19.
Beatriz A Rodas-Junco Yahaira Cab-Guillen J Armando Mu?oz-Sanchez Felipe Vázquez-Flota Miriam Monforte-Gonzalez S M Teresa Hérnandez-Sotomayor 《Plant signaling & behavior》2013,8(10)
Signal transduction via phospholipids is mediated by phospholipases such as phospholipase C (PLC) and D (PLD), which catalyze hydrolysis of plasma membrane structural phospholipids. Phospholipid signaling is also involved in plant responses to phytohormones such as salicylic acid (SA). The relationships between phospholipid signaling, SA, and secondary metabolism are not fully understood. Using a Capsicum chinense cell suspension as a model, we evaluated whether phospholipid signaling modulates SA-induced vanillin production through the activation of phenylalanine ammonia lyase (PAL), a key enzyme in the biosynthetic pathway. Salicylic acid was found to elicit PAL activity and consequently vanillin production, which was diminished or reversed upon exposure to the phosphoinositide-phospholipase C (PI-PLC) signaling inhibitors neomycin and . Exposure to the phosphatidic acid inhibitor 1-butanol altered PLD activity and prevented SA-induced vanillin production. Our results suggest that PLC and PLD-generated secondary messengers may be modulating SA-induced vanillin production through the activation of key biosynthetic pathway enzymes. U73122相似文献
20.
Neha Dixit Dennis J Wu Yesser H Belgacem Laura N Borodinsky M Eric Gershwin Iannis E Adamopoulos 《Arthritis research & therapy》2014,16(6)