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Christophe Delye - One of the best experts on this subject based on the ideXlab platform.
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universAl pcr AssAys detecting mutAtions in Acetyl Coenzyme A cArboxylAse or AcetolActAte synthAse thAt endow herbicide resistAnce in grAss weeds
Weed Research, 2011Co-Authors: Christophe Delye, Fanny Pernin, Séverine MichelAbstract:Delye C, Pernin F & Michel S (2011). ‘UniversAl’ PCR AssAys detecting mutAtions in Acetyl-Coenzyme A cArboxylAse or AcetolActAte synthAse thAt endow herbicide resistAnce in grAss weeds. Weed ReseArch51, 353–362. SummAry Herbicides inhibiting Acetyl-Coenzyme A cArboxylAse (ACCAse) or AcetolActAte synthAse (ALS) Are key for grAss weed control. Yet, numerous cAses of resistAnce hAve evolved. Using the derived cleAved Amplified polymorphic sequence method, we developed moleculAr AssAys to detect Amino Acid replAcements At the seven ACCAse codons (1781, 1999, 2027, 2041, 2078, 2088 And 2096) And At two ALS codons (197 And 574) known to plAy A role in herbicide resistAnce in grAss weeds. For eAch codon, one AssAy detecting All known Amino Acid replAcements endowing herbicide resistAnce wAs developed. The nine AssAys were successfully used to genotype ACCAse And ALS in 39 grAss species. Their flexible design enAbles eAsy detection of new mutAtions At the tArgeted codons. BecAuse they cAn be implemented with bAsic moleculAr biology fAcilities And no previous knowledge of the ACCAse or ALS sequence of the grAss weed of interest, these AssAys Are tools of choice to eAsily detect resistAnce cAused by AlterAtion(s) of ACCAse or ALS in such species.
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geogrAphicAl vAriAtion in resistAnce to Acetyl Coenzyme A cArboxylAse inhibiting herbicides Across the rAnge of the ArAble weed Alopecurus myosuroides blAck grAss
New Phytologist, 2010Co-Authors: Christophe Delye, Jean-philippe Guillemin, Séverine Michel, Bruno Chauvel, Aurelie Berard, Dominique Brunel, Fabrice Dessaint, Valerie Le CorreAbstract:SummAry • The geogrAphicAl structure of resistAnce to herbicides inhibiting Acetyl-Coenzyme A cArboxylAse (ACCAse) wAs investigAted in the weed Alopecurus myosuroides (blAck-grAss) Across its geogrAphicAl rAnge to gAin insight into the process of plAnt AdAptAtion in response to Anthropogenic selective pressures occurring in AgriculturAl ecosystems. • We AnAlysed 297 populAtions distributed Across six countries in A. myosuroides’ mAin AreA of occupAncy. The frequencies of plAnts resistAnt to two broAdly used ACCAse inhibitors And of seven mutAnt, resistAnt ACCAse Alleles were Assessed using bioAssAys And genotyping, respectively. • Most of the resistAnce wAs not endowed by mutAnt ACCAse Alleles. ResistAnce And ACCAse Allele distribution pAtterns were chArActerized by mosAicism. The prevAlence of resistAnce And of ACCAse Alleles differed Among countries. • ResistAnce cleArly evolved by redundAnt evolution of A set of resistAnce Alleles or genes, most of which remAin unidentified. ResistAnce in A. myosuroides wAs shAped by vAriAtion in the herbicide selective pressure At both the individuAl field level And the nAtionAl level.
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Complex genetic control of non-tArget-site-bAsed resistAnce to herbicides inhibiting Acetyl-Coenzyme A cArboxylAse And AcetolActAte-synthAse in Alopecurus myosuroides Huds.
Plant Science, 2010Co-Authors: Cécile Petit, Bastien Duhieu, Karelle Boucansaud, Christophe DelyeAbstract:The genetic control of non-tArget-site-bAsed resistAnce (NTSR) to three herbicides inhibiting Acetyl-Coenzyme A cArboxylAse (ACCAse) And one inhibiting AcetolActAte-synthAse (ALS) wAs investigAted in Alopecurus myosuroides (blAck-grAss). Hundred controlled pAirings were used to determine the minimum number of loci involved in NTSR to eAch herbicide And their AssociAted resistAnce pAttern. ResistAnt pArentAl plAnts survived herbicide doses rAnging from 1 to 12 times the field rAte. In A single plAnt, NTSR to A given herbicide involved At leAst one to three dominAnt loci or one recessive locus. AccumulAtion of up to At leAst three NTSR loci in A single plAnt could be necessAry to confer resistAnce. Most NTSR loci endowing resistAnce to one herbicide did not confer detectAble resistAnce to Any other herbicide AssAyed. This is the first study demonstrAting thAt NTSR is A quAntitAtive trAit. It Also reveAled three nested levels of complexity in NTSR: the loci, which cAn confer resistAnce At the whole plAnt level depending on the herbicide And on the dose used; the individuAl plAnts, which cAn AccumulAte vArious sets of NTSR loci viA sexuAl reproduction; And the populAtions, which Are mAde of vArious frequencies of genotypes eAch contAining different numbers And combinAtions of NTSR loci.
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StAtus of blAck-grAss (Alopecurus myosuroides) resistAnce to Acetyl-Coenzyme A cArboxylAse inhibitors in FrAnce
Weed Research, 2007Co-Authors: Christophe Delye, Yosra Menchari, Jean-philippe Guillemin, Annick Matejicek, Séverine Michel, Christine Camilleri, Bruno ChauvelAbstract:We Assessed the contributions of tArget site- And non-tArget site-bAsed resistAnce to herbicides inhibiting Acetyl-Coenzyme A cArboxylAse (ACC) in Alopecurus myosuroides (blAck grAss). A totAl of 243 A. myosuroides populAtions collected Across FrAnce were AnAlysed using herbicide sensitivity bioAssAy (24 300 seedlings AnAlysed) And ACC genotyping (13 188 seedlings AnAlysed). Seedlings resistAnt to At leAst one ACC-inhibiting herbicide were detected in 99.2% of the populAtions. MutAnt, resistAnt ACC Allele(s) were detected in 56.8% of the populAtions. Among the five resistAnt ACC Alleles known in A. myosuroides, Alleles contAining An isoleucine-to-leucine substitution At codon 1781 were predominAnt (59.5% of the plAnts contAining resistAnt ACC Alleles). CompArison of the results from herbicide sensitivity bioAssAys with genotyping indicAted thAt more thAn 75% of the plAnts resistAnt to ACC-inhibiting herbicides in FrAnce would be resistAnt viA increAsed herbicide metAbolism. AnAlysis of herbicide ApplicAtion records suggested thAt in 15.9% of the populAtions studied, metAbolism-bAsed resistAnce to ACC-inhibiting herbicides wAs mostly selected for by herbicides with other modes of Action. Our study reveAled the importAnce of non-tArget site-bAsed resistAnce in A. myosuroides. Using herbicides with AlternAtive modes of Action to control populAtions resistAnt to ACC-inhibiting herbicides, the recommended mAnAgement ApproAch, mAy thus be jeopArdised by the widespreAd occurrence of metAbolism-bAsed resistAnce mechAnisms conferring broAd-spectrum cross-resistAnce
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moleculAr bAses for sensitivity to Acetyl Coenzyme A cArboxylAse inhibitors in blAck grAss
Plant Physiology, 2005Co-Authors: Christophe Delye, Annick Matejicek, Séverine Michel, Xiaoqi Zhang, Stephen B PowlesAbstract:In grAsses, residues homologous to residues Ile-1,781 And Ile-2,041 in the cArboxyl-trAnsferAse (CT) domAin of the chloroplAstic Acetyl-Coenzyme A (CoA) cArboxylAse (ACCAse) from the grAss weed blAck-grAss (Alopecurus myosuroides [Huds.]) Are criticAl determinAnts for sensitivity to two clAsses of ACCAse inhibitors, AryloxyphenoxypropionAtes (APPs) And cyclohexAnediones. Using nAturAl mutAnts of blAck-grAss, we demonstrAted through A moleculAr, biologicAl, And biochemicAl ApproAch thAt residues Trp-2,027, Asp-2,078, And Gly-2,096 Are Also involved in sensitivity to ACCAse inhibitors. In Addition, residues Trp-2,027 And Asp-2,078 Are very likely involved in CT Activity. Using three-dimensionAl modeling, we found thAt the side chAins of the five residues Are AdjAcent, locAted At the surfAce of the inside of the cAvity of the CT Active site, in the vicinity of the binding site for APPs. Residues 1,781 And 2,078 Are involved in sensitivity to both APPs And cyclohexAnediones, whereAs residues 2,027, 2,041, And 2,096 Are involved in sensitivity to APPs only. This suggests thAt the binding sites for these two clAsses of compounds Are overlApping, Although distinct. CompArison of three-dimensionAl models for blAck-grAss wild-type And mutAnt CTs And for CTs from orgAnisms with contrAsted sensitivity to ACCAse inhibitors suggested thAt inhibitors fitting into the cAvity of the CT Active site of the chloroplAstic ACCAse from grAsses to reAch their Active sites mAy be tight. The three-dimensionAl shApe of this cAvity is thus likely of high importAnce for the efficAcy of ACCAse inhibitors.
Antonius J A Van Maris - One of the best experts on this subject based on the ideXlab platform.
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engineering cytosolic Acetyl Coenzyme A supply in sAcchAromyces cerevisiAe pAthwAy stoichiometry free energy conservAtion And redox cofActor bAlAncing
Metabolic Engineering, 2016Co-Authors: Harmen M Van Rossum, Jack T Pronk, Barbara U Kozak, Antonius J A Van MarisAbstract:SAcchAromyces cerevisiAe is An importAnt industriAl cell fActory And An AttrActive experimentAl model for evAluAting novel metAbolic engineering strAtegies. MAny current And potentiAl products of this yeAst require Acetyl Coenzyme A (Acetyl-CoA) As A precursor And pAthwAys towArds these products Are generAlly expressed in its cytosol. The nAtive S. cerevisiAe pAthwAy for production of cytosolic Acetyl-CoA consumes 2 ATP equivAlents in the Acetyl-CoA synthetAse reAction. CAtAbolism of AdditionAl sugAr substrAte, which mAy be required to generAte this ATP, negAtively Affects product yields. Here, we review AlternAtive pAthwAys thAt cAn be engineered into yeAst to optimize supply of cytosolic Acetyl-CoA As A precursor for product formAtion. PArticulAr Attention is pAid to reAction stoichiometry, free-energy conservAtion And redox-cofActor bAlAncing of AlternAtive pAthwAys for Acetyl-CoA synthesis from glucose. A theoreticAl AnAlysis of mAximAlly AttAinAble yields on glucose of four compounds (n-butAnol, citric Acid, pAlmitic Acid And fArnesene) showed A strong product dependency of the optimAl pAthwAy configurAtion for Acetyl-CoA synthesis. Moreover, this AnAlysis showed thAt combinAtion of different Acetyl-CoA production pAthwAys mAy be required to Achieve optimAl product yields. This review underlines thAt An integrAl AnAlysis of energy coupling And redox-cofActor bAlAncing in precursor-supply And product-formAtion pAthwAys is cruciAl for the design of efficient cell fActories.
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engineering Acetyl Coenzyme A supply functionAl expression of A bActeriAl pyruvAte dehydrogenAse complex in the cytosol of sAcchAromyces cerevisiAe
Mbio, 2014Co-Authors: Barbara U Kozak, Jack T Pronk, Harmen M Van Rossum, Marijke A H Luttik, Michiel Akeroyd, Kirsten R Benjamin, Simon De Vries, Jeanmarc Daran, Antonius J A Van MarisAbstract:The energetic (ATP) cost of biochemicAl pAthwAys criticAlly determines the mAximum yield of metAbolites of vitAl or commerciAl relevAnce. Cytosolic Acetyl Coenzyme A (Acetyl-CoA) is A key precursor for biosynthesis in eukAryotes And for mAny industriAlly relevAnt product pAthwAys thAt hAve been introduced into SAcchAromyces cerevisiAe, such As isoprenoids or lipids. In this yeAst, synthesis of cytosolic Acetyl-CoA viA Acetyl-CoA synthetAse (ACS) involves hydrolysis of ATP to AMP And pyrophosphAte. Here, we demonstrAte thAt expression And Assembly in the yeAst cytosol of An ATP-independent pyruvAte dehydrogenAse complex (PDH) from Enterococcus fAecAlis cAn fully replAce the ACS-dependent pAthwAy for cytosolic Acetyl-CoA synthesis. In vivo Activity of E. fAecAlis PDH required simultAneous expression of E. fAecAlis genes encoding its E1α, E1β, E2, And E3 subunits, As well As genes involved in lipoylAtion of E2, And Addition of lipoAte to growth mediA. A strAin lAcking ACS thAt expressed these E. fAecAlis genes grew At neAr-wild-type rAtes on glucose synthetic medium supplemented with lipoAte, under Aerobic And AnAerobic conditions. A physiologicAl compArison of the engineered strAin And An isogenic Acs(+) reference strAin showed smAll differences in biomAss yields And metAbolic fluxes. CellulAr frActionAtion And gel filtrAtion studies reveAled thAt the E. fAecAlis PDH subunits were Assembled in the yeAst cytosol, with A subunit rAtio And enzyme Activity similAr to vAlues reported for PDH purified from E. fAecAlis. This study indicAtes thAt cytosolic expression And Assembly of PDH in eukAryotic industriAl microorgAnisms is A promising option for minimizing the energy costs of precursor supply in Acetyl-CoA-dependent product pAthwAys. ImportAnce: GeneticAlly engineered microorgAnisms Are intensively investigAted And Applied for production of biofuels And chemicAls from renewAble sugArs. To mAke such processes economicAlly And environmentAlly sustAinAble, the energy (ATP) costs for product formAtion from sugAr must be minimized. Here, we focus on An importAnt ATP-requiring process in bAker's yeAst (SAcchAromyces cerevisiAe): synthesis of cytosolic Acetyl Coenzyme A, A key precursor for mAny industriAlly importAnt products, rAnging from biofuels to frAgrAnces. We demonstrAte thAt pyruvAte dehydrogenAse from the bActerium Enterococcus fAecAlis, A huge enzyme complex with A size similAr to thAt of A ribosome, cAn be functionAlly expressed And Assembled in the cytosol of bAker's yeAst. Moreover, we show thAt this ATP-independent mechAnism for cytosolic Acetyl-CoA synthesis cAn entirely replAce the ATP-costly nAtive yeAst pAthwAy. This work provides metAbolic engineers with A new option to optimize the performAnce of bAker's yeAst As A "cell fActory" for sustAinAble production of fuels And chemicAls.
Barbara U Kozak - One of the best experts on this subject based on the ideXlab platform.
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engineering cytosolic Acetyl Coenzyme A supply in sAcchAromyces cerevisiAe pAthwAy stoichiometry free energy conservAtion And redox cofActor bAlAncing
Metabolic Engineering, 2016Co-Authors: Harmen M Van Rossum, Jack T Pronk, Barbara U Kozak, Antonius J A Van MarisAbstract:SAcchAromyces cerevisiAe is An importAnt industriAl cell fActory And An AttrActive experimentAl model for evAluAting novel metAbolic engineering strAtegies. MAny current And potentiAl products of this yeAst require Acetyl Coenzyme A (Acetyl-CoA) As A precursor And pAthwAys towArds these products Are generAlly expressed in its cytosol. The nAtive S. cerevisiAe pAthwAy for production of cytosolic Acetyl-CoA consumes 2 ATP equivAlents in the Acetyl-CoA synthetAse reAction. CAtAbolism of AdditionAl sugAr substrAte, which mAy be required to generAte this ATP, negAtively Affects product yields. Here, we review AlternAtive pAthwAys thAt cAn be engineered into yeAst to optimize supply of cytosolic Acetyl-CoA As A precursor for product formAtion. PArticulAr Attention is pAid to reAction stoichiometry, free-energy conservAtion And redox-cofActor bAlAncing of AlternAtive pAthwAys for Acetyl-CoA synthesis from glucose. A theoreticAl AnAlysis of mAximAlly AttAinAble yields on glucose of four compounds (n-butAnol, citric Acid, pAlmitic Acid And fArnesene) showed A strong product dependency of the optimAl pAthwAy configurAtion for Acetyl-CoA synthesis. Moreover, this AnAlysis showed thAt combinAtion of different Acetyl-CoA production pAthwAys mAy be required to Achieve optimAl product yields. This review underlines thAt An integrAl AnAlysis of energy coupling And redox-cofActor bAlAncing in precursor-supply And product-formAtion pAthwAys is cruciAl for the design of efficient cell fActories.
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engineering Acetyl Coenzyme A supply functionAl expression of A bActeriAl pyruvAte dehydrogenAse complex in the cytosol of sAcchAromyces cerevisiAe
Mbio, 2014Co-Authors: Barbara U Kozak, Jack T Pronk, Harmen M Van Rossum, Marijke A H Luttik, Michiel Akeroyd, Kirsten R Benjamin, Simon De Vries, Jeanmarc Daran, Antonius J A Van MarisAbstract:The energetic (ATP) cost of biochemicAl pAthwAys criticAlly determines the mAximum yield of metAbolites of vitAl or commerciAl relevAnce. Cytosolic Acetyl Coenzyme A (Acetyl-CoA) is A key precursor for biosynthesis in eukAryotes And for mAny industriAlly relevAnt product pAthwAys thAt hAve been introduced into SAcchAromyces cerevisiAe, such As isoprenoids or lipids. In this yeAst, synthesis of cytosolic Acetyl-CoA viA Acetyl-CoA synthetAse (ACS) involves hydrolysis of ATP to AMP And pyrophosphAte. Here, we demonstrAte thAt expression And Assembly in the yeAst cytosol of An ATP-independent pyruvAte dehydrogenAse complex (PDH) from Enterococcus fAecAlis cAn fully replAce the ACS-dependent pAthwAy for cytosolic Acetyl-CoA synthesis. In vivo Activity of E. fAecAlis PDH required simultAneous expression of E. fAecAlis genes encoding its E1α, E1β, E2, And E3 subunits, As well As genes involved in lipoylAtion of E2, And Addition of lipoAte to growth mediA. A strAin lAcking ACS thAt expressed these E. fAecAlis genes grew At neAr-wild-type rAtes on glucose synthetic medium supplemented with lipoAte, under Aerobic And AnAerobic conditions. A physiologicAl compArison of the engineered strAin And An isogenic Acs(+) reference strAin showed smAll differences in biomAss yields And metAbolic fluxes. CellulAr frActionAtion And gel filtrAtion studies reveAled thAt the E. fAecAlis PDH subunits were Assembled in the yeAst cytosol, with A subunit rAtio And enzyme Activity similAr to vAlues reported for PDH purified from E. fAecAlis. This study indicAtes thAt cytosolic expression And Assembly of PDH in eukAryotic industriAl microorgAnisms is A promising option for minimizing the energy costs of precursor supply in Acetyl-CoA-dependent product pAthwAys. ImportAnce: GeneticAlly engineered microorgAnisms Are intensively investigAted And Applied for production of biofuels And chemicAls from renewAble sugArs. To mAke such processes economicAlly And environmentAlly sustAinAble, the energy (ATP) costs for product formAtion from sugAr must be minimized. Here, we focus on An importAnt ATP-requiring process in bAker's yeAst (SAcchAromyces cerevisiAe): synthesis of cytosolic Acetyl Coenzyme A, A key precursor for mAny industriAlly importAnt products, rAnging from biofuels to frAgrAnces. We demonstrAte thAt pyruvAte dehydrogenAse from the bActerium Enterococcus fAecAlis, A huge enzyme complex with A size similAr to thAt of A ribosome, cAn be functionAlly expressed And Assembled in the cytosol of bAker's yeAst. Moreover, we show thAt this ATP-independent mechAnism for cytosolic Acetyl-CoA synthesis cAn entirely replAce the ATP-costly nAtive yeAst pAthwAy. This work provides metAbolic engineers with A new option to optimize the performAnce of bAker's yeAst As A "cell fActory" for sustAinAble production of fuels And chemicAls.
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engineering Acetyl Coenzyme A supply functionAl expression of A bActeriAl pyruvAte dehydrogenAse complex in the cytosol of sAcchAromyces cerevisiAe
Mbio, 2014Co-Authors: Barbara U Kozak, Jack T Pronk, Marijke A H Luttik, Michiel Akeroyd, Kirsten R Benjamin, Simon De Vries, Jeanmarc Daran, Harmen M Van Rossum, Liang Wu, Antonius J A Van MarisAbstract:The energetic (ATP) cost of biochemicAl pAthwAys criticAlly determines the mAximum yield of metAbolites of vitAl or commerciAl relevAnce. Cytosolic Acetyl Coenzyme A (Acetyl-CoA) is A key precursor for biosynthesis in eukAryotes And for mAny industriAlly relevAnt product pAthwAys thAt hAve been introduced into SAcchAromyces cerevisiAe, such As isoprenoids or lipids. In this yeAst, synthesis of cytosolic Acetyl-CoA viA Acetyl-CoA synthetAse (ACS) involves hydrolysis of ATP to AMP And pyrophosphAte. Here, we demonstrAte thAt expression And Assembly in the yeAst cytosol of An ATP-independent pyruvAte dehydrogenAse complex (PDH) from Enterococcus fAecAlis cAn fully replAce the ACS-dependent pAthwAy for cytosolic Acetyl-CoA synthesis. In vivo Activity of E. fAecAlis PDH required simultAneous expression of E. fAecAlis genes encoding its E1?, E1?, E2, And E3 subunits, As well As genes involved in lipoylAtion of E2, And Addition of lipoAte to growth mediA. A strAin lAcking ACS thAt expressed these E. fAecAlis genes grew At neAr-wild-type rAtes on glucose synthetic medium supplemented with lipoAte, under Aerobic And AnAerobic conditions. A physiologicAl compArison of the engineered strAin And An isogenic Acs+ reference strAin showed smAll differences in biomAss yields And metAbolic fluxes. CellulAr frActionAtion And gel filtrAtion studies reveAled thAt the E. fAecAlis PDH subunits were Assembled in the yeAst cytosol, with A subunit rAtio And enzyme Activity similAr to vAlues reported for PDH purified from E. fAecAlis. This study indicAtes thAt cytosolic expression And Assembly of PDH in eukAryotic industriAl microorgAnisms is A promising option for minimizing the energy costs of precursor supply in Acetyl-CoA-dependent product pAthwAys.
Valerie Le Corre - One of the best experts on this subject based on the ideXlab platform.
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geogrAphicAl vAriAtion in resistAnce to Acetyl Coenzyme A cArboxylAse inhibiting herbicides Across the rAnge of the ArAble weed Alopecurus myosuroides blAck grAss
New Phytologist, 2010Co-Authors: Christophe Delye, Jean-philippe Guillemin, Séverine Michel, Bruno Chauvel, Aurelie Berard, Dominique Brunel, Fabrice Dessaint, Valerie Le CorreAbstract:SummAry • The geogrAphicAl structure of resistAnce to herbicides inhibiting Acetyl-Coenzyme A cArboxylAse (ACCAse) wAs investigAted in the weed Alopecurus myosuroides (blAck-grAss) Across its geogrAphicAl rAnge to gAin insight into the process of plAnt AdAptAtion in response to Anthropogenic selective pressures occurring in AgriculturAl ecosystems. • We AnAlysed 297 populAtions distributed Across six countries in A. myosuroides’ mAin AreA of occupAncy. The frequencies of plAnts resistAnt to two broAdly used ACCAse inhibitors And of seven mutAnt, resistAnt ACCAse Alleles were Assessed using bioAssAys And genotyping, respectively. • Most of the resistAnce wAs not endowed by mutAnt ACCAse Alleles. ResistAnce And ACCAse Allele distribution pAtterns were chArActerized by mosAicism. The prevAlence of resistAnce And of ACCAse Alleles differed Among countries. • ResistAnce cleArly evolved by redundAnt evolution of A set of resistAnce Alleles or genes, most of which remAin unidentified. ResistAnce in A. myosuroides wAs shAped by vAriAtion in the herbicide selective pressure At both the individuAl field level And the nAtionAl level.
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nucleotide vAriAbility At the Acetyl Coenzyme A cArboxylAse gene And the signAture of herbicide selection in the grAss weed Alopecurus myosuroides huds
Molecular Biology and Evolution, 2004Co-Authors: Christophe Delye, Séverine Michel, Cecile Straub, Valerie Le CorreAbstract:Acetyl Coenzyme A cArboxylAse (ACCAse) is the tArget of highly effective herbicides. We investigAted the nucleotide vAriAbility of the ACCAse gene in A sAmple of 18 blAck-grAss (Alopecurus myosuroides [Huds.]) populAtions to seArch for the signAture of herbicide selection. Sequencing 3,396 bp encompAssing ACCAse herbicide-binding domAin in 86 individuAls reveAled 92 polymorphisms, which formed 72 hAplotypes. The rAtio of nonsynonymous versus synonymous substitutions wAs very low, in Agreement with ACCAse being A vitAl metAbolic enzyme. Within blAck grAss, most nonsynonymous substitutions were relAted to resistAnce to ACCAse-inhibiting herbicides. DifferentiAtion between populAtions wAs strong, in contrAst to expectAtions for An AllogAmous, AnnuAl plAnt. SignificAnt H tests reveAled recent hitchhiking events within populAtions. These results were consistent with recent And locAl positive selection. We propose thAt, Although they hAve only been used since At most 15 blAck-grAss generAtions, ACCAse-inhibiting herbicides hAve exerted A positive selection tArgeting resistAnt hAplotypes thAt hAs been strong enough to hAve A mArked effect upon ACCAse nucleotide diversity. A minimum-spAnning network of nonrecombinAnt hAplotypes reveAled multiple, independent AppAritions of resistAnce-AssociAted mutAtions. This study provides the first evidence for the signAture of ongoing, recent, pesticide selection upon vAriAtion At the gene encoding the tArgeted enzyme in nAturAl plAnt populAtions.
Jorge C Escalantesemerena - One of the best experts on this subject based on the ideXlab platform.
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pAnm An Acetyl Coenzyme A sensor required for mAturAtion of l AspArtAte decArboxylAse pAnd
Mbio, 2012Co-Authors: Tara N Stuecker, Alex C Tucker, Jorge C EscalantesemerenaAbstract:Coenzyme A (CoA) is essentiAl for cellulAr chemistry in All forms of life. The pAntothenAte moiety of CoA is generAted from the condensAtion of pAntoAte And -AlAnine.-AlAnine is formed by decArboxylAtion of L-AspArtAte cAtAlyzed by PAnD, A pyruvoyl enzyme thAt is synthesized by the cell As An inActive precursor (pro-PAnD). MAturAtion of pro-PAnD into PAnD occurs viA A self-cleAvAge event At residue Ser25, which forms the cAtAlytic pyruvoyl moiety. We recently reported thAt SAlmonellA en- tericA PAnM wAs necessAry for pro-PAnD mAturAtion, both in vitro And in vivo. NotAbly, PAnM is AnnotAted As A Gcn5-like N-AcetyltrAnsferAse (GNAT), which suggested thAt lysine AcetylAtion might be pArt of the mechAnism of mAturAtion. Here we show thAt PAnM lAcks AcetyltrAnsferAse Activity And thAt Acetyl-CoA stimulAtes its Activity. Results of experiments with nonhy- drolyzAble ethyl-CoA And geneticAlly encoded Acetyl-lysine-contAining PAnD support the conclusion thAt PAnM-dependent pro- PAnD mAturAtion does not involve An Acetyl trAnsfer event. We Also show thAt CoA binding to PAnM is needed for in vivo Activity And thAt disruption of CoA binding prevents PAnM from interActing with PAnD. We conclude thAt PAnM is A GNAT homologue thAt lost its AcetyltrAnsferAse Activity And evolved A new function As An Acetyl-CoA sensor thAt cAn trigger the mAturAtion of pro- PAnD. IMPORTANCE N-lysine AcetylAtion is increAsingly being recognized As A widespreAd And importAnt form of posttrAnslAtionAl regulAtion in bActeriA. The AcetyltrAnsferAses thAt cAtAlyze these reActions Are poorly chArActerized in bActeriA. BAsed on AnnotA- tion, most bActeriAl genomes contAin severAl AcetyltrAnsferAses, but the physiologicAl roles of only A hAndful hAve been deter- mined. NotAbly, A subset of putAtive AcetyltrAnsferAses lAck residues thAt Are criticAl for Activity in most biochemicAlly chArActer- ized AcetyltrAnsferAses. We show thAt one such putAtive AcetyltrAnsferAse, PAnM (formerly YhhK), lAcks AcetyltrAnsferAse Activity but functions insteAd As An Acetyl-Coenzyme A (CoA) sensor. This work estAblishes the possibility thAt, like PAnM, other putAtive AcetyltrAnsferAses mAy hAve evolved new functions while retAining the Ability to sense Acetyl-CoA.
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biochemicAl And mutAtionAl AnAlyses of AcuA the AcetyltrAnsferAse enzyme thAt controls the Activity of the Acetyl Coenzyme A synthetAse AcsA in bAcillus subtilis
Journal of Bacteriology, 2008Co-Authors: Jeffrey G Gardner, Jorge C EscalantesemerenaAbstract:The AcuABC genes of BAcillus subtilis comprise A putAtive posttrAnslAtionAl modificAtion system. The AcuA protein is A member of the Gcn5-relAted N-AcetyltrAnsferAse (GNAT) superfAmily, the AcuC protein is A clAss I histone deAcetylAse, And the role of the AcuB protein is not known. AcuA controls the Activity of Acetyl Coenzyme A synthetAse (AcsA; EC 6.2.1.1) in this bActerium by AcetylAting residue Lys549. Here we report the kinetic AnAlysis of wild-type And vAriAnt AcuA proteins. We contrived A genetic scheme for the identificAtion of AcuA residues criticAl for Activity. ChAnges At residues H177 And G187 completely inActivAted AcuA And led to its rApid turnover. ChAnges At residues R42 And T169 were less severe. In vitro AssAy conditions were optimized, And An effective meAns of inActivAting the enzyme wAs found. The bAsic kinetic pArAmeters of wild-type And vAriAnt AcuA proteins were obtAined And compAred to those of eukAryotic GNATs. Insights into how the isolAted mutAtions mAy exert their deleterious effect were investigAted by using the crystAl structure of An AcuA homolog.
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control of Acetyl Coenzyme A synthetAse AcsA Activity by AcetylAtion deAcetylAtion without nAd involvement in bAcillus subtilis
Journal of Bacteriology, 2006Co-Authors: Jeffrey G Gardner, Frank J Grundy, Tina M Henkin, Jorge C EscalantesemerenaAbstract:PosttrAnslAtionAl modificAtion is An efficient mechAnism for controlling the Activity of structurAl proteins, gene expression regulAtors, And enzymes in response to rApidly chAnging physiologicAl conditions. Here we report in vitro And in vivo evidence thAt the AcuABC operon of the grAm-positive soil bActerium BAcillus subtilis encodes A protein AcetyltrAnsferAse (AcuA) And A protein deAcetylAse (AcuC), which mAy control the Activity of Acetyl-Coenzyme A (CoA) synthetAse (AMP-forming, AcsA) in this bActerium. Results from in vitro experiments using purified proteins show thAt AcsA is A substrAte for the Acetyl-CoA-dependent AcuA AcetyltrAnsferAse. MAss spectrometry AnAlysis of A tryptic digest of AcetylAted AcsA (AcsAAc) identified residue Lys549 As the sole modificAtion site in the protein. Unlike sirtuins, the AcuC protein did not require NAD+ As cosubstrAte to deAcetylAte AcsAAc. The function of the putAtive AcuB protein remAins unknown.
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Acetyl Coenzyme A synthetAse Amp forming
Cellular and Molecular Life Sciences, 2004Co-Authors: Vincent J Starai, Jorge C EscalantesemerenaAbstract:Acetyl-Coenzyme A synthetAse (AMP forming; Acs) is An enzyme whose Activity is centrAl to the metAbolism of prokAryotic And eukAryotic cells. The physiologicAl role of this enzyme is to ActivAte AcetAte to Acetyl-Coenzyme A (Ac-CoA). The importAnce of Acs hAs been recognized for decAdes, since it provides the cell the two-cArbon metAbolite used in mAny AnAbolic And energy generAtion processes. In the lAst decAde reseArchers hAve leArned how cArefully the cell monitors the synthesis And Activity of this enzyme. In eukAryotes And prokAryotes, complex regulAtory systems control Acs gene expression As A function cArbon flux, with A second lAyer of regulAtion exerted posttrAnslAtionAlly by the NAD+/sirtuin-dependent protein AcetylAtion/deAcetylAtion system. Recent structurAl work provides snApshots of the drAmAtic conformAtionAl chAnges Acs undergoes during cAtAlysis. Future work on the regulAtion of Acs gene expression will expAnd our understAnding of metAbolic integrAtion, while structure/function studies will reveAl more detAils of the function of this splendid moleculAr mAchine.