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Alan M Jones - One of the best experts on this subject based on the ideXlab platform.

  • photosynthate reGulation of the root system architecture mediated by the Heterotrimeric G Protein complex in arabidopsis
    Frontiers in Plant Science, 2016
    Co-Authors: Yashwanti Mudgil, Abhijit Karve, Paulo Jose Pereira Lima Teixeira, Kun Jiang, Meral Tuncozdemir, Alan M Jones
    Abstract:

    Assimilate partitioninG to the root system is a desirable developmental trait to control but little is known of the siGnalinG pathway underlyinG partitioninG. A null mutation in the Gene encodinG the Gβ subunit of the Heterotrimeric G Protein complex, a nexus for a variety of siGnalinG pathways, confers altered suGar partitioninG in roots. While fixed carbon rapidly reached the roots of wild type and aGb1-2 mutant seedlinGs, aGb1 roots had more of this fixed carbon in the form of Glucose, fructose, and sucrose which manifested as a hiGher lateral root density. Upon Glucose treatment, the aGb1-2 mutant had abnormal Gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization and level was altered in the aGb1-2 mutant. The Heterotrimeric G Protein complex inteGrates photosynthesis-derived suGar siGnalinG incorporatinG both membrane-and transcriptional-based mechanisms. The time constants for these siGnalinG mechanisms are in the same ranGe as photosynthate delivery to the root, raisinG the possibility that root cells are able to use chanGes in carbon fixation in real time to adjust Growth behavior.

  • photosynthate reGulation of the root system architecture mediated by the Heterotrimeric G Protein complex in arabidopsis
    Frontiers in Plant Science, 2016
    Co-Authors: Yashwanti Mudgil, Abhijit Karve, Paulo Jose Pereira Lima Teixeira, Kun Jiang, Meral Tuncozdemir, Alan M Jones
    Abstract:

    Assimilate partitioninG to the root system is a desirable developmental trait to control but little is known of the siGnalinG pathway underlyinG partitioninG. A null mutation in the Gene encodinG the Gβ subunit of the Heterotrimeric G Protein complex, a nexus for a variety of siGnalinG pathways, confers altered suGar partitioninG in roots. While fixed carbon rapidly reached the roots of wild type and aGb1-2 mutant seedlinGs, aGb1 roots had more of this fixed carbon in the form of Glucose, fructose, and sucrose which manifested as a hiGher lateral root density. Upon Glucose treatment, the aGb1-2 mutant had abnormal Gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization was altered in the aGb1-2 mutant. The Heterotrimeric G Protein complex inteGrates photosynthesis-derived suGar siGnalinG incorporatinG both membrane-and transcriptional-based mechanisms. The time constants for these siGnalinG mechanisms are in the same ranGe as photosynthate delivery to the root, raisinG the possibility that root cells are able to use chanGes in carbon fixation in real time to adjust Growth behavior.

  • plant morpholoGy of Heterotrimeric G Protein mutants
    Plant and Cell Physiology, 2016
    Co-Authors: Yukimoto Iwasaki, Daisuke Urano, Kotaro Miura, David Jackson, Alan M Jones
    Abstract:

    The Heterotrimeric G Protein complex, comprisinG Gα, Gγ and Gγ subunits, is an evolutionarily conserved siGnalinG molecular machine that transmits siGnals from transmembrane receptors to downstream tarGet Proteins. Plants conserved the core G Protein elements, while developinG their own reGulatory systems differently from animals. Genetic evidence supports the conclusion that the Heterotrimeric G Proteins reGulate shoot, root and epidermis development, as well as suGar sensinG, hormone responsiveness and abiotic and biotic stress tolerance. This review is a compendium of the known morpholoGical chanGes conferred by loss- and Gain-of-function mutations of the G Protein subunit Genes across three hiGher land plant models, namely Arabidopsis, rice and maize.

  • Heterotrimeric G Protein siGnallinG in the plant kinGdom
    Open Biology, 2013
    Co-Authors: Daisuke Urano, Jingui Chen, Jose Ramon Botella, Alan M Jones
    Abstract:

    In animals, Heterotrimeric G Proteins, comprisinG α-, β-and γ-subunits, perceive extracellular stimuli throuGh cell surface receptors, and transmit siGnals to ion channels, enzymes and other effect...

  • Glucose attenuation of auxin mediated bimodality in lateral root formation is partly coupled by the Heterotrimeric G Protein complex
    PLOS ONE, 2010
    Co-Authors: Katherine S Booker, John Schwarz, Michelle B Garrett, Alan M Jones
    Abstract:

    BackGround Auxin and Glucose are both essential elements in normal root development. The Heterotrimeric G Protein complex in Arabidopsis thaliana, defined as containinG alpha (AtGPA1), beta (AGB1), and Gamma (AGG) subunits and a GTPase acceleratinG Protein called ReGulator of G SiGnalinG 1 Protein (AtRGS1), are involved in Glucose siGnalinG and reGulate auxin transport. MethodoloGy/Principal FindinGs A systems approach was used to show that formation of lateral roots, a process requirinG coordinated cell division followed by tarGeted cell expansion, involves a siGnalinG interaction between Glucose and auxin. We dissected the relationship between auxin and Glucose action usinG lateral root formation as the bioloGical context. We found that auxin and Glucose act synerGistically to yield a complex output involvinG both stimulatory and antaGonist Glucose effects on auxin responsiveness. Auxin-induced, lateral-root formation becomes bimodal with reGard to auxin dose in the presence of Glucose. This bimodality is mediated, in part, by the G Protein complex defined above. Conclusion/SiGnificance Auxin and Glucose are essential siGnals controllinG the rate of cell proliferation and expansion in roots. Auxin promotes the formation of lateral roots and is consequently essential for proper root architecture. Glucose affects the activation state of the Heterotrimeric G Protein complex which reGulates auxin distribution in the root. The bimodality of auxin-induced, lateral-root formation becomes prominent in the presence of Glucose and in roots lackinG the G Protein complex. Bimodality is apparent without added Glucose in all loss-of-function mutants for these G Protein components, suGGestinG that the Heterotrimeric G Protein complex attenuates the bimodality and that Glucose inhibits this attenuation throuGh the complex. The bimodality can be further resolved into the processes of lateral root primordia formation and lateral root emerGence, from which a model inteGratinG these siGnals is proposed.

Yashwanti Mudgil - One of the best experts on this subject based on the ideXlab platform.

  • photosynthate reGulation of the root system architecture mediated by the Heterotrimeric G Protein complex in arabidopsis
    Frontiers in Plant Science, 2016
    Co-Authors: Yashwanti Mudgil, Abhijit Karve, Paulo Jose Pereira Lima Teixeira, Kun Jiang, Meral Tuncozdemir, Alan M Jones
    Abstract:

    Assimilate partitioninG to the root system is a desirable developmental trait to control but little is known of the siGnalinG pathway underlyinG partitioninG. A null mutation in the Gene encodinG the Gβ subunit of the Heterotrimeric G Protein complex, a nexus for a variety of siGnalinG pathways, confers altered suGar partitioninG in roots. While fixed carbon rapidly reached the roots of wild type and aGb1-2 mutant seedlinGs, aGb1 roots had more of this fixed carbon in the form of Glucose, fructose, and sucrose which manifested as a hiGher lateral root density. Upon Glucose treatment, the aGb1-2 mutant had abnormal Gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization and level was altered in the aGb1-2 mutant. The Heterotrimeric G Protein complex inteGrates photosynthesis-derived suGar siGnalinG incorporatinG both membrane-and transcriptional-based mechanisms. The time constants for these siGnalinG mechanisms are in the same ranGe as photosynthate delivery to the root, raisinG the possibility that root cells are able to use chanGes in carbon fixation in real time to adjust Growth behavior.

  • photosynthate reGulation of the root system architecture mediated by the Heterotrimeric G Protein complex in arabidopsis
    Frontiers in Plant Science, 2016
    Co-Authors: Yashwanti Mudgil, Abhijit Karve, Paulo Jose Pereira Lima Teixeira, Kun Jiang, Meral Tuncozdemir, Alan M Jones
    Abstract:

    Assimilate partitioninG to the root system is a desirable developmental trait to control but little is known of the siGnalinG pathway underlyinG partitioninG. A null mutation in the Gene encodinG the Gβ subunit of the Heterotrimeric G Protein complex, a nexus for a variety of siGnalinG pathways, confers altered suGar partitioninG in roots. While fixed carbon rapidly reached the roots of wild type and aGb1-2 mutant seedlinGs, aGb1 roots had more of this fixed carbon in the form of Glucose, fructose, and sucrose which manifested as a hiGher lateral root density. Upon Glucose treatment, the aGb1-2 mutant had abnormal Gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization was altered in the aGb1-2 mutant. The Heterotrimeric G Protein complex inteGrates photosynthesis-derived suGar siGnalinG incorporatinG both membrane-and transcriptional-based mechanisms. The time constants for these siGnalinG mechanisms are in the same ranGe as photosynthate delivery to the root, raisinG the possibility that root cells are able to use chanGes in carbon fixation in real time to adjust Growth behavior.

Renato Chavez - One of the best experts on this subject based on the ideXlab platform.

  • Heterotrimeric G Protein alpha subunit controls Growth stress response extracellular protease activity and cyclopiazonic acid production in penicillium camemberti
    Fungal Biology, 2017
    Co-Authors: Ramon O Garciarico, Inmaculada Vaca, Carlos Gilduran, Juan F Rojasaedo, Luis Figueroa, Gloria Levican, Renato Chavez
    Abstract:

    The funGus Penicillium camemberti is widely used in the ripeninG of various bloomy-rind cheeses. Several properties of P. camemberti are important in cheese ripeninG, includinG conidiation, Growth and enzyme production, amonG others. However, the production of mycotoxins such as cyclopiazonic acid durinG the ripeninG process by P. camemberti has raised concerns amonG consumers that demand food with minimal contamination. Here we show that overexpressinG an α-subunit from the subGroup I of the Heterotrimeric G Protein (Gαi) influences several of these processes: it neGatively affects Growth in a media-dependent manner, triGGers conidial Germination, reduces the rate of sporulation, affects thermal and osmotic stress resistance, and also extracellular protease and cyclopiazonic acid production. Our results contribute to understandinG the bioloGical determinants underlyinG these bioloGical processes in the economically important funGus P. camemberti.

  • effect of a Heterotrimeric G Protein α subunit on conidia Germination stress response and roquefortine c production in penicillium roqueforti
    International Microbiology, 2009
    Co-Authors: Ramon O Garciarico, Renato Chavez, Francisco Fierro, Juan F Martin
    Abstract:

    Heterotrimeric G Protein siGnalinG reGulates many processes in funGi, such as development, pathoGenicity, and secondary metabolite biosynthesis. For example, the Galpha subunit PGa1 from Penicillium chrysoGenum reGulates conidiation and secondary metabolite production in this funGus. The dominant activatinG allele, pGa1G42R, encodinG a constitutively active PGa1 Galpha subunit, was introduced in Penicillium roqueforti by transformation, resultinG in a phenotype characterized by low sporulation and slow Growth. In this work, the effect of the constitutively active PGa1G42R Galpha subunit on conidial Germination, stress tolerance, and roquefortine C production of P. roqueforti was studied. PGa1G42R triGGered Germination in the absence of a carbon source, in addition to neGatively reGulatinG thermal and osmotic stress tolerance. The presence of the PGa1G42R Galpha subunit also had an important effect on roquefortine C biosynthesis, increasinG production and maintaininG hiGh levels of the mycotoxin throuGhout a culture period of 30 days. ToGether, the results suGGest that G Protein-mediated siGnalinG participates in the reGulation of these three processes in P. roqueforti.

Yukimoto Iwasaki - One of the best experts on this subject based on the ideXlab platform.

  • Identification of Heterotrimeric G Protein γ3 Subunit in Rice Plasma Membrane
    'MDPI AG', 2018
    Co-Authors: Aki Nishiyama, Kotaro Miura, Sakura Matsuta, Genki Chaya, Takafumi Itoh, Yukimoto Iwasaki
    Abstract:

    Heterotrimeric G Proteins are important molecules for reGulatinG plant architecture and transmittinG external siGnals to intracellular tarGet Proteins in hiGher plants and mammals. The rice Genome contains one canonical α subunit Gene (RGA1), four extra-larGe GTP-bindinG Protein Genes (XLGs), one canonical β subunit Gene (RGB1), and five γ subunit Genes (tentatively named RGG1, RGG2, RGG3/GS3/Mi/OsGGC1, RGG4/DEP1/DN1/OsGGC3, and RGG5/OsGGC2). RGG1 encodes the canonical γ subunit; RGG2 encodes the plant-specific type of γ subunit with additional amino acid residues at the N-terminus; and the remaininG three γ subunit Genes encode the atypical γ subunits with cysteine abundance at the C-terminus. We aimed to identify the RGG3/GS3/Mi/OsGGC1 Gene product, Gγ3, in rice tissues usinG the anti-Gγ3 domain antibody. We also analyzed the truncated Protein, Gγ3∆Cys, in the RGG3/GS3/Mi/OsGGC1 mutant, Mi, usinG the anti-Gγ3 domain antibody. Based on nano-liquid chromatoGraphy-tandem mass spectrometry (LC-MS/MS) analysis, the immunoprecipitated Gγ3 candidates were confirmed to be Gγ3. Similar to α (Gα) and β subunits (Gβ), Gγ3 was enriched in the plasma membrane fraction, and accumulated in the flower tissues. As RGG3/GS3/Mi/OsGGC1 mutants show the characteristic phenotype in flowers and consequently in seeds, the tissues that accumulated Gγ3 corresponded to the abnormal tissues observed in RGG3/GS3/Mi/OsGGC1 mutants

  • plant morpholoGy of Heterotrimeric G Protein mutants
    Plant and Cell Physiology, 2016
    Co-Authors: Yukimoto Iwasaki, Daisuke Urano, Kotaro Miura, David Jackson, Alan M Jones
    Abstract:

    The Heterotrimeric G Protein complex, comprisinG Gα, Gγ and Gγ subunits, is an evolutionarily conserved siGnalinG molecular machine that transmits siGnals from transmembrane receptors to downstream tarGet Proteins. Plants conserved the core G Protein elements, while developinG their own reGulatory systems differently from animals. Genetic evidence supports the conclusion that the Heterotrimeric G Proteins reGulate shoot, root and epidermis development, as well as suGar sensinG, hormone responsiveness and abiotic and biotic stress tolerance. This review is a compendium of the known morpholoGical chanGes conferred by loss- and Gain-of-function mutations of the G Protein subunit Genes across three hiGher land plant models, namely Arabidopsis, rice and maize.

  • suppression of the rice Heterotrimeric G Protein β subunit Gene rGb1 causes dwarfism and browninG of internodes and lamina joint reGions
    Plant Journal, 2011
    Co-Authors: Yuzuko Utsunomiya, Yukiko Fujisawa, Chihiro Samejima, Yoshiyuki Takayanagi, Yuki Izawa, Takahisa Yoshida, Yuka Sawada, Hisaharu Kato, Yukimoto Iwasaki
    Abstract:

    In the present study, we investiGated the function of the Heterotrimeric G Protein β-subunit (Gβ) Gene (RGB1) in rice. RGB1 knock-down lines were Generated in the wild type and d1-5, a mutant deficient for the Heterotrimeric G Protein α-subunit (Gα) Gene (RGA1). Both transGenic lines showed browninG of the lamina joint reGions and nodes that could be attributed to a reduction of RGB1 function, as the abnormality was not observed in d1-5. The RGB1 knock-down lines Generated in d1-5 were shorter, suGGestinG RGB1 to be a positive reGulator of cellular proliferation, in addition to RGA1. The number of sterile seeds also increased in both RGB1 knock-down lines. These results suGGest that Gβγ and Gα cooperatively function in cellular proliferation and seed fertility. We discuss the potential predominant role of RGB1 in G Protein siGnalinG in rice.

  • the Heterotrimeric G Protein α subunit acts upstream of the small Gtpase rac in disease resistance of rice
    Proceedings of the National Academy of Sciences of the United States of America, 2002
    Co-Authors: Utut Widyastuti Suharsono, Hikaru Satoh, Yukiko Fujisawa, Yukimoto Iwasaki, Tsutomu Kawasaki, Ko Shimamoto
    Abstract:

    We used rice dwarf1 (d1) mutants lackinG a sinGle-copy Gα Gene and addressed Gα's role in disease resistance. d1 mutants exhibited a hiGhly reduced hypersensitive response to infection by an avirulent race of rice blast. Activation of PR Gene expression in the leaves of the mutants infected with rice blast was delayed for 24 h relative to the wild type. H2O2 production and PR Gene expression induced by sphinGolipid elicitors (SE) were stronGly suppressed in d1 cell cultures. Expression of the constitutively active OsRac1, a small GTPase Rac of rice, in d1 mutants restored SE-dependent defense siGnalinG and resistance to rice blast. Gα mRNA was induced by an avirulent race of rice blast and SE application on the leaf. These results indicated the role of Gα in R Gene-mediated disease resistance of rice. We have proposed a model for the defense siGnalinG of rice in which the Heterotrimeric G Protein functions upstream of the small GTPase OsRac1 in the early steps of siGnalinG.

  • rice dwarf mutant d1 which is defective in the α subunit of the Heterotrimeric G Protein affects Gibberellin siGnal transduction
    Proceedings of the National Academy of Sciences of the United States of America, 2000
    Co-Authors: Miyako Ueguchitanaka, Yukiko Fujisawa, Masatomo Kobayashi, Yukimoto Iwasaki, Hidemi Kitano, Motoyuki Ashikari, Makoto Matsuoka
    Abstract:

    Previously, we reported that the rice dwarf mutant, d1, is defective in the α subunit of the Heterotrimeric G Protein (Gα). In the present study, Gibberellin (GA) siGnalinG in d1 and the role of the Gα Protein in the GA-siGnalinG pathway were investiGated. Compared with the wild type, GA induction of α-amylase activity in aleurone cells of d1 was Greatly reduced. Relative to the wild type, the GA3-treated aleurone layer of d1 had lower expression of Ramy1A, which encodes α-amylase, and OsGAMYB, which encodes a GA-inducible transcriptional factor, and no increase in expression of Ca2 +-ATPase. However, in the presence of hiGh GA concentrations, α-amylase induction occurred even in d1. The GA sensitivity of second leaf sheath elonGation in d1 was similar to that of the wild type in terms of dose responsiveness, but the response of internode elonGation to GA was much lower in d1. Furthermore, Os20ox expression was up-reGulated, and the GA content was elevated in the stunted internodes of d1. All these results suGGest that d1 affects a part of the GA-siGnalinG pathway, namely the induction of α-amylase in the aleurone layer and internode elonGation. In addition, a double mutant between d1 and another GA-siGnalinG mutant, slr, revealed that SLR is epistatic to the D1, supportinG that the Gα Protein is involved in GA siGnalinG. However, the data also provide evidence for the presence of an alternative GA-siGnalinG pathway that does not involve the Gα Protein. It is proposed that GA siGnalinG via the Gα Protein may be more sensitive than that of the alternative pathway, as indicated by the low GA responsiveness of this Gα-independent pathway.

Heidi E. Hamm - One of the best experts on this subject based on the ideXlab platform.

  • Heterotrimeric G Protein activation by G Protein coupled receptors
    Nature Reviews Molecular Cell Biology, 2008
    Co-Authors: William M. Oldham, Heidi E. Hamm
    Abstract:

    Heterotrimeric G Proteins have a crucial role as molecular switches in siGnal transduction pathways mediated by G-Protein-coupled receptors. Extracellular stimuli activate these receptors, which then catalyse GTP-GDP exchanGe on the G Protein alpha-subunit. The complex series of interactions and conformational chanGes that connect aGonist bindinG to G Protein activation raise various interestinG questions about the structure, biomechanics, kinetics and specificity of siGnal transduction across the plasma membrane.

  • the 2 0 a crystal structure of a Heterotrimeric G Protein
    Nature, 1996
    Co-Authors: Heidi E. Hamm, David G Lambright, John Sondek, A Bohm, Nikolai P Skiba, Paul B Sigler
    Abstract:

    The structure of a Heterotrimeric G Protein reveals the mechanism of the nucleotide-dependent enGaGement of the α and βγ subunits that reGulates their interaction with receptor and effector molecules. The interaction involves two distinct interfaces and dramatically alters the conformation of the αbut not of theβγ subunits. The location of the known sites for posttranslational modification and receptor couplinG suGGest a plausible orientation with respect to the membrane surface and an activated heptahelical receptor.

  • structural determinants for activation of the alpha subunit of a Heterotrimeric G Protein
    Nature, 1994
    Co-Authors: David G Lambright, Heidi E. Hamm, Joseph P Noel, Paul B Sigler
    Abstract:

    The 1.8 A crystal structure of transducin α-GDP, when compared to that of the activated complex with GTP-γS, reveals the nature of the conformational chanGes that occur on activation of a Heterotrimeric G-Protein α-subunit. Structural chanGes initiated by direct contacts with the terminal phosphate of GTP propaGate to reGions that have been implicated in effector activation. The chanGes are distinct from those observed in other members of the GTPase superfamily.