Martinez M

References (16)

Title : Withanolides from Datura ceratocaula and Datura discolor and their acetylcholinesterase inhibitory activity - Gonzalez_2023_Fitoterapia_170_105655
Author(s) : Gonzalez U , Nieto-Camacho A , Hernandez-Ortega S , Martinez M , Maldonado E
Ref : Fitoterapia , 170 :105655 , 2023
Abstract : The investigation of the chemical constituents of Datura ceratocaula and D. discolor allowed to isolate three new withanolides, datucerolide A (1) from the first species, and datudiscolides A (8) and B (9) from the second. In addition, seven known withanolides and five ubiquitous compounds were isolated from these plants, along with 27-O-beta-d-glucopyranosyl dinnoxolide A (5), which was obtained as the tetraacetyl derivative 4. All the structures were elucidated by analyses of their spectroscopic and spectrometric data and that of dinnoxolide A (6) was confirmed by X-ray diffraction analysis. The structure 4 was assigned earlier to daturametelin G-Ac and that of 5 to datinolide B, therefore, it will be discussed whether these assignments are correct. On the other hand, the structure of datudiscolide A (8) was previously assigned to the aglycone of dinoxin B (14), however, a revision of its reported NMR data showed inconsistencies with the proposed structure. The inhibitory activity of withanolides 2, 3, 6-8, 12, and 13 against acetylcholinesterase enzyme (AChE) was evaluated. Compounds 6, 7, 12, and 13 exhibited the best activity with IC(50) values ranging from 2.8 to 21.5 microM.
ESTHER : Gonzalez_2023_Fitoterapia_170_105655
PubMedSearch : Gonzalez_2023_Fitoterapia_170_105655
PubMedID: 37595646

Title : Hydroxynitrile lyase defends Arabidopsis against Tetranychus urticae - Arnaiz_2022_Plant.Physiol_189_2244
Author(s) : Arnaiz A , Santamaria ME , Rosa-Diaz I , Garcia I , Dixit S , Vallejos S , Gotor C , Martinez M , Grbic V , Diaz I
Ref : Plant Physiol , 189 :2244 , 2022
Abstract : Plant-pest interactions involve multifaceted processes encompassing a complex crosstalk of pathways, molecules, and regulators aimed at overcoming defenses developed by each interacting organism. Among plant defensive compounds against phytophagous arthropods, cyanide-derived products are toxic molecules that directly target pest physiology. Here, we identified the Arabidopsis (Arabidopsis thaliana) gene encoding hydroxynitrile lyase (AtHNL, At5g10300) as one gene induced in response to spider mite (Tetranychus urticae) infestation. AtHNL catalyzes the reversible interconversion between cyanohydrins and derived carbonyl compounds with free cyanide. AtHNL loss- and gain-of-function Arabidopsis plants showed that specific activity of AtHNL using mandelonitrile as substrate was higher in the overexpressing lines than in wild-type (WT) and mutant lines. Concomitantly, mandelonitrile accumulated at higher levels in mutant lines than in WT plants and was significantly reduced in the AtHNL overexpressing lines. After mite infestation, mandelonitrile content increased in WT and overexpressing plants but not in mutant lines, while hydrogen cyanide (HCN) accumulated in the three infested Arabidopsis genotypes. Feeding bioassays demonstrated that the AtHNL gene participated in Arabidopsis defense against T. urticae. The reduced leaf damage detected in the AtHNL overexpressing lines reflected the mite's reduced ability to feed on leaves, which consequently restricted mite fecundity. In turn, mites upregulated TuCAS1 encoding beta-cyanoalanine synthase to avoid the respiratory damage produced by HCN. This detoxification effect was functionally demonstrated by reduced mite fecundity observed when dsRNA-TuCAS-treated mites fed on WT plants and hnl1 mutant lines. These findings add more players in the Arabidopsis-T. urticae interplay to overcome mutual defenses.
ESTHER : Arnaiz_2022_Plant.Physiol_189_2244
PubMedSearch : Arnaiz_2022_Plant.Physiol_189_2244
PubMedID: 35474139
Gene_locus related to this paper: arath-HNL

Title : Labdanes, Withanolides, and Other Constituents from Physalis nicandroides - Torres_2019_J.Nat.Prod_82_2489
Author(s) : Torres FR , Perez-Castorena AL , Arredondo L , Toscano RA , Nieto-Camacho A , Martinez M , Maldonado E
Ref : Journal of Natural Products , 82 :2489 , 2019
Abstract : Chemical investigation of the aerial parts (except fruits and calixes) of Physalis nicandroides var. attenuata led to the isolation of a series of new labdane-type diterpenoids, including the closely related compounds 1-3, the labdane glucosides 4 and 5, a mixture of the epimeric alcohols 6 and 7, and one labdanetriol, isolated as its tri-O-acetyl derivative 9. In addition, three new withanolides (14-16) and six known compounds were isolated. The structures of these compounds were elucidated by analysis of their spectroscopic data and chemical transformations, and those of compounds 1, 4, and 16 were confirmed by X-ray diffraction analysis of the natural product (1) and of the corresponding acetyl derivatives 4a and 16a. Fourteen of these compounds were assayed for their in vitro inhibitory activity against yeast alpha-glucosidase and acetylcholinesterase enzymes. The results were negative in both cases, except for compound 3a that marginally inhibited the activity of acetylcholinesterase with an IC50 value of 64.4 muM.
ESTHER : Torres_2019_J.Nat.Prod_82_2489
PubMedSearch : Torres_2019_J.Nat.Prod_82_2489
PubMedID: 31429569

Title : Plant Defenses Against Pests Driven by a Bidirectional Promoter - Arnaiz_2019_Front.Plant.Sci_10_930
Author(s) : Arnaiz A , Martinez M , Gonzalez-Melendi P , Grbic V , Diaz I , Santamaria ME
Ref : Front Plant Sci , 10 :930 , 2019
Abstract : The plant defense responses to pests results in the synchronized change of a complex network of interconnected genes and signaling pathways. An essential part of this process is mediated by the binding of transcription factors to the specific responsive cis-elements within in the promoters of phytophagous-responsive genes. In this work, it is reported the identification and characterization of a bidirectional promoter that simultaneously co-regulate two divergent genes, At5g10300 and At5g10290, upon arthropod feeding. Computational analysis identified the presence of cis-elements within the intergenic region between two loci, mainly from the DOF but also from the AP2/ERF, Golden 2-like and bHLH families. The function of the bidirectional promoter was analyzed using two enhanced variants of the GFP and CherryFP reporter genes, in both orientations, in transient tobacco and stably transformed Arabidopsis plants. Promoter activity was tested in response to feeding of Tetranychus urticae and Pieris brassicae, as well as wounding, flagellin and chitin treatments. Using RT-qPCR assays and confocal microscopy, it was shown that all treatments resulted in the induction of both reporter genes. Furthermore, our findings revealed the asymmetric character of the promoter with stronger activity in the forward than in the reverse orientation. This study provides an example of a bidirectional promoter with a strong potential to be used in plant biotechnology in pest control that requires stacking of the defense genes.
ESTHER : Arnaiz_2019_Front.Plant.Sci_10_930
PubMedSearch : Arnaiz_2019_Front.Plant.Sci_10_930
PubMedID: 31379907
Gene_locus related to this paper: arath-HNL

Title : Solvent-free lipase-catalyzed synthesis of a novel hydroxyl-fatty acid derivative of kojic acid - El-Boulifi_2014_Enzyme.Microb.Technol_55_128
Author(s) : El-Boulifi N , Ashari SE , Serrano M , Aracil J , Martinez M
Ref : Enzyme Microb Technol , 55 :128 , 2014
Abstract : The aim of this work was the synthesis of a novel hydroxyl-fatty acid derivative of kojic acid rich in kojic acid monoricinoleate (KMR) which can be widely used in the cosmetic and food industry. The synthesis of KMR was carried out by lipase-catalysed esterification of ricinoleic and kojic acids in solvent-free system. Three immobilized lipases were tested and the best KMR yields were attained with Lipozyme TL IM and Novozym 435. Since Lipozyme TL IM is the cheapest, it was selected to optimize the reaction conditions. The optimal reaction conditions were 80 degreeC for the temperature, 1:1 for the alcohol/acid molar ratio, 600 rpm for stirring speed and 7.8% for the catalyst concentration. Under these conditions, the reaction was scaled up in a 5x10-3 m3 stirred tank reactor. 1H-13C HMBC-NMR showed that the primary hydroxyl group of kojic acid was regioselectively esterified. The KMR has more lipophilicity than kojic acid and showed antioxidant activity that improves the oxidation stability of biodiesel.
ESTHER : El-Boulifi_2014_Enzyme.Microb.Technol_55_128
PubMedSearch : El-Boulifi_2014_Enzyme.Microb.Technol_55_128
PubMedID: 24411455

Title : The effect of an aloe polymannose multinutrient complex on cognitive and immune functioning in Alzheimer's disease - Lewis_2013_J.Alzheimers.Dis_33_393
Author(s) : Lewis JE , McDaniel HR , Agronin ME , Loewenstein DA , Riveros J , Mestre R , Martinez M , Colina N , Abreu D , Konefal J , Woolger JM , Ali KH
Ref : J Alzheimers Dis , 33 :393 , 2013
Abstract : Alzheimer's disease (AD) is a leading killer of Americans, imparts a significant toll on the quality of life of the patient and primary caregiver, and results in inordinate costs in an already overburdened medical system. Prior studies on cholinesterase inhibitors among AD patients have shown minimal amelioration of disease symptoms and/or restoration of lost cognitive functioning. The effect of improved nutrition, particularly with dietary supplements, on cognitive functioning may offer an alternative strategy compared to standard treatment. The present pilot study investigated the effect of an aloe polymannose multinutrient complex (APMC) formula on cognitive and immune functioning over 12 months among adults diagnosed with AD. Subjects participated in an open-label trial and consumed 4 teaspoons per day of the APMC. The ADAS-cog, MMSE, ADCS-ADL, and SIB were administered at baseline and 3, 6, 9, and 12 months follow-up. Cytokines and lymphocyte and monocyte subsets were assessed at baseline and 12 months. The mean ADAS-cog cognition score significantly improved at 9 and 12 months from baseline, and 46% of our sample showed clinically-significant improvement (>/=4-point change) from baseline to 12 months. Participants showed significant decreases in tumor necrosis factor-alpha, vascular endothelial growth factor, and interleukins-2 and-4. CD90+, CD95+CD3+, CD95+CD34+, CD95+CD90+, CD14+CD34+, CD14+CD90+, and CD14+CD95+ decreased significantly, whereas CD14+ significantly increased. Participants tolerated the APMC supplement with few, temporary adverse reactions. Our results showed improvements in both clinical and physiological outcomes for a disease that otherwise has no standard ameliorative remedy.
ESTHER : Lewis_2013_J.Alzheimers.Dis_33_393
PubMedSearch : Lewis_2013_J.Alzheimers.Dis_33_393
PubMedID: 22976077

Title : The genome of Tetranychus urticae reveals herbivorous pest adaptations - Grbic_2011_Nature_479_487
Author(s) : Grbic M , Van Leeuwen T , Clark RM , Rombauts S , Rouze P , Grbic V , Osborne EJ , Dermauw W , Ngoc PC , Ortego F , Hernandez-Crespo P , Diaz I , Martinez M , Navajas M , Sucena E , Magalhaes S , Nagy L , Pace RM , Djuranovic S , Smagghe G , Iga M , Christiaens O , Veenstra JA , Ewer J , Villalobos RM , Hutter JL , Hudson SD , Velez M , Yi SV , Zeng J , Pires-daSilva A , Roch F , Cazaux M , Navarro M , Zhurov V , Acevedo G , Bjelica A , Fawcett JA , Bonnet E , Martens C , Baele G , Wissler L , Sanchez-Rodriguez A , Tirry L , Blais C , Demeestere K , Henz SR , Gregory TR , Mathieu J , Verdon L , Farinelli L , Schmutz J , Lindquist E , Feyereisen R , Van de Peer Y
Ref : Nature , 479 :487 , 2011
Abstract : The spider mite Tetranychus urticae is a cosmopolitan agricultural pest with an extensive host plant range and an extreme record of pesticide resistance. Here we present the completely sequenced and annotated spider mite genome, representing the first complete chelicerate genome. At 90 megabases T. urticae has the smallest sequenced arthropod genome. Compared with other arthropods, the spider mite genome shows unique changes in the hormonal environment and organization of the Hox complex, and also reveals evolutionary innovation of silk production. We find strong signatures of polyphagy and detoxification in gene families associated with feeding on different hosts and in new gene families acquired by lateral gene transfer. Deep transcriptome analysis of mites feeding on different plants shows how this pest responds to a changing host environment. The T. urticae genome thus offers new insights into arthropod evolution and plant-herbivore interactions, and provides unique opportunities for developing novel plant protection strategies.
ESTHER : Grbic_2011_Nature_479_487
PubMedSearch : Grbic_2011_Nature_479_487
PubMedID: 22113690
Gene_locus related to this paper: tetur-ACHE

Title : Lipase-catalyzed synthesis of isosorbide monoricinoleate: process optimization by response surface methodology - El Boulifi_2010_Bioresour.Technol_101_8520
Author(s) : El Boulifi N , Aracil J , Martinez M
Ref : Bioresour Technol , 101 :8520 , 2010
Abstract : A new ester of natural origin was prepared by esterification of 1,4:3,6-dianhydro-d-glucitol (isosorbide) with a long-chain fatty acid (ricinoleic), using immobilized enzyme catalyst in non-solvent system. Renewable raw materials produced from carbohydrates and oil biorefineries were used as basic substances in this study. Response surface methodology (RSM) based on central composite design was used to optimize the main important reaction variables - catalyst concentration (2.2-7.8%) wt and temperature (60-80 degrees C). Using RSM, quadratic model was developed to correlate the preparation variable to the responses (isosorbide mono- and diricinoleate yield). It was found that the most effective parameter was temperature. The optimum combination derived via RSM for producing the high monoester yield (93%) and low diester yield (1.7%) was found to be 6.2% wt catalyst concentration at a reaction temperature of 63 degrees C during 2h of reaction time.
ESTHER : El Boulifi_2010_Bioresour.Technol_101_8520
PubMedSearch : El Boulifi_2010_Bioresour.Technol_101_8520
PubMedID: 20638275

Title : Genome characteristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography - Normand_2007_Genome.Res_17_7
Author(s) : Normand P , Lapierre P , Tisa LS , Gogarten JP , Alloisio N , Bagnarol E , Bassi CA , Berry AM , Bickhart DM , Choisne N , Couloux A , Cournoyer B , Cruveiller S , Daubin V , Demange N , Francino MP , Goltsman E , Huang Y , Kopp OR , Labarre L , Lapidus A , Lavire C , Marechal J , Martinez M , Mastronunzio JE , Mullin BC , Niemann J , Pujic P , Rawnsley T , Rouy Z , Schenowitz C , Sellstedt A , Tavares F , Tomkins JP , Vallenet D , Valverde C , Wall LG , Wang Y , Medigue C , Benson DR
Ref : Genome Res , 17 :7 , 2007
Abstract : Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N(2)-fixing root nodules on diverse and globally distributed angiosperms in the "actinorhizal" symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%-98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses.
ESTHER : Normand_2007_Genome.Res_17_7
PubMedSearch : Normand_2007_Genome.Res_17_7
PubMedID: 17151343
Gene_locus related to this paper: frasn-a8leg3 , fraaa-q0rau9 , fraaa-q0rbj9 , fraaa-q0rc03 , fraaa-q0rc89 , fraaa-q0rci1 , fraaa-q0rdx4 , fraaa-q0ref4 , fraaa-q0rel4 , fraaa-q0req5 , fraaa-q0rev2 , fraaa-q0rfl4 , fraaa-q0rfz5 , fraaa-q0rhz6 , fraaa-q0rjm3 , fraaa-q0rjt2 , fraaa-q0rkm8 , fraaa-q0rkv5 , fraaa-q0rl43 , fraaa-q0rlp9 , fraaa-q0rm04 , fraaa-q0rmn2 , fraaa-q0rmz5 , fraaa-q0rqg7 , fraaa-q0rr69 , fraaa-q0rrm7 , fraaa-q0rs07 , fraaa-q0rt07 , fraaa-q0rt55 , fraaa-q0rt70 , fraaa-q0rt91 , fraaa-q0rtc4 , fraaa-q0rte4 , fraaa-q0rtv2 , fraaa-q0rum6 , frasc-q2j5v5 , frasc-q2j8e6 , frasc-q2jct6 , frasn-a8kx42 , frasn-a8kyp2 , frasn-A8L0F8 , frasn-a8l0g7 , frasn-a8l1j7 , frasn-a8l1t9 , frasn-a8l4h8 , frasn-a8l7f8 , frasn-a8l8i4 , frasn-a8l8k8 , frasn-a8l9e9 , frasn-a8l051 , frasn-a8l115 , frasn-a8l161 , frasn-a8l265 , frasn-a8l268 , frasn-a8l720 , frasn-a8l745 , frasn-a8l755 , frasn-a8l875 , frasn-a8lab3 , frasn-a8lag3 , frasn-a8lb99 , frasn-a8lbd8 , frasn-a8lbj7 , frasn-a8lbj8 , frasn-a8lby7 , frasn-a8ldb7 , frasn-a8ldd0 , frasn-a8le91 , frasn-a8leg6 , frasn-a8leq6 , frasn-a8let0 , frasn-a8lf43 , frasn-a8lfg3 , frasn-a8lfl1 , frasn-a8lgw1 , frasn-a8lgy1 , frasc-q2j553 , frasn-a8l2m3 , fraaa-q0rd38 , frasc-q2j6h2 , frasn-a8lfl3 , frasn-a8leg7 , frasn-a8l5b8 , fraaa-q0rgz4 , fraaa-q0rtv3 , frasn-a8le98 , frasn-a8leb4

Title : Genome sequence and analysis of the soil cellulolytic actinomycete Thermobifida fusca YX - Lykidis_2007_J.Bacteriol_189_2477
Author(s) : Lykidis A , Mavromatis K , Ivanova N , Anderson I , Land M , DiBartolo G , Martinez M , Lapidus A , Lucas S , Copeland A , Richardson P , Wilson DB , Kyrpides N
Ref : Journal of Bacteriology , 189 :2477 , 2007
Abstract : Thermobifida fusca is a moderately thermophilic soil bacterium that belongs to Actinobacteria. It is a major degrader of plant cell walls and has been used as a model organism for the study of secreted, thermostable cellulases. The complete genome sequence showed that T. fusca has a single circular chromosome of 3,642,249 bp predicted to encode 3,117 proteins and 65 RNA species with a coding density of 85%. Genome analysis revealed the existence of 29 putative glycoside hydrolases in addition to the previously identified cellulases and xylanases. The glycosyl hydrolases include enzymes predicted to exhibit mainly dextran/starch- and xylan-degrading functions. T. fusca possesses two protein secretion systems: the sec general secretion system and the twin-arginine translocation system. Several of the secreted cellulases have sequence signatures indicating their secretion may be mediated by the twin-arginine translocation system. T. fusca has extensive transport systems for import of carbohydrates coupled to transcriptional regulators controlling the expression of the transporters and glycosylhydrolases. In addition to providing an overview of the physiology of a soil actinomycete, this study presents insights on the transcriptional regulation and secretion of cellulases which may facilitate the industrial exploitation of these systems.
ESTHER : Lykidis_2007_J.Bacteriol_189_2477
PubMedSearch : Lykidis_2007_J.Bacteriol_189_2477
PubMedID: 17209016
Gene_locus related to this paper: thefu-q6a0i3 , thefy-q47l17 , thefy-q47p38 , thefy-q47pm5

Title : Acetylcholinesterase genes within the Diptera: takeover and loss in true flies - Huchard_2006_Proc.Biol.Sci_273_2595
Author(s) : Huchard E , Martinez M , Alout H , Douzery EJ , Lutfalla G , Berthomieu A , Berticat C , Raymond M , Weill M
Ref : Proc Biol Sci , 273 :2595 , 2006
Abstract : It has recently been reported that the synaptic acetylcholinesterase (AChE) in mosquitoes is encoded by the ace-1 gene, distinct and divergent from the ace-2 gene, which performs this function in Drosophila. This is an unprecedented situation within the Diptera order because both ace genes derive from an old duplication and are present in most insects and arthropods. Nevertheless, Drosophila possesses only the ace-2 gene. Thus, a secondary loss occurred during the evolution of Diptera, implying a vital function switch from one gene (ace-1) to the other (ace-2). We sampled 78 species, representing 50 families (27% of the Dipteran families) spread over all major subdivisions of the Diptera, and looked for ace-1 and ace-2 by systematic PCR screening to determine which taxonomic groups within the Diptera have this gene change. We show that this loss probably extends to all true flies (or Cyclorrhapha), a large monophyletic group of the Diptera. We also show that ace-2 plays a non-detectable role in the synaptic AChE in a lower Diptera species, suggesting that it has non-synaptic functions. A relative molecular evolution rate test showed that the intensity of purifying selection on ace-2 sequences is constant across the Diptera, irrespective of the presence or absence of ace-1, confirming the evolutionary importance of non-synaptic functions for this gene. We discuss the evolutionary scenarios for the takeover of ace-2 and the loss of ace-1, taking into account our limited knowledge of non-synaptic functions of ace genes and some specific adaptations of true flies.
ESTHER : Huchard_2006_Proc.Biol.Sci_273_2595
PubMedSearch : Huchard_2006_Proc.Biol.Sci_273_2595
PubMedID: 17002944
Gene_locus related to this paper: culpi-ACHE1 , culpi-ACHE2 , drobs-ACHE2 , drosi-ACHE , drowi-ACHE , gloff-ACHE2

Title : The -2 bp deletion in exon 6 of the 'alpha 7-like' nicotinic receptor subunit gene is a risk factor for the P50 sensory gating deficit - Raux_2002_Mol.Psychiatry_7_1006
Author(s) : Raux G , Bonnet-Brilhault F , Louchart S , Houy E , Gantier R , Levillain D , Allio G , Haouzir S , Petit M , Martinez M , Frebourg T , Thibaut F , Campion D
Ref : Mol Psychiatry , 7 :1006 , 2002
Abstract : Abnormality in the P50 auditory-evoked potential gating is an endophenotype associated with schizophrenia. Biochemical and genetic studies have suggested that the alpha 7 nicotinic acetylcholine receptor (nAChR) is involved in this sensory gating deficit. Two related alpha 7 genes (CHRNA7 and CHRNA7-like gene) resulting from a partial duplication (from exon 5 to exon 10) are present in the human genome. Two types of genetic variation, a large deletion and a -2 base-pair deletion in exon 6 resulting in a truncation of the open reading frame, affect specifically the CHRNA7-like gene. We developed a simple multiplex PCR assay on genomic DNA, allowing the quantification of the number of exons 6 and the distinction of all possible exon 6 genotypes. Genotyping of 70 schizophrenic patients and 77 controls showed that carrying at least one -2 bp deletion of exon 6 did not constitute a risk factor for schizophrenia. In contrast, the distribution of genotypes differed significantly between subjects with normal and abnormal P50 ratios, with an over-representation of genotypes carrying at least one -2 bp deletion of exon 6 among subjects exhibiting an abnormal P50 ratio. We thus conclude that the -2 bp deletion within the CHRNA7-like gene is a risk factor for P50 sensory gating deficit. Interestingly, most of the effect came from the non schizophrenic group, which may suggest that in schizophrenic patients other risk factors account for the large proportion of subjects exhibiting an abnormal P50 ratio.
ESTHER : Raux_2002_Mol.Psychiatry_7_1006
PubMedSearch : Raux_2002_Mol.Psychiatry_7_1006
PubMedID: 12399955

Title : Novel Biodegradable Aromatic Plastics from a Bacterial Source. Genetic and biochemical studies on a route of the phenylacetyl-coa catabolon - Garcia_1999_J.Biol.Chem_274_29228
Author(s) : Garcia B , Olivera ER , Minambres B , Fernandez-Valverde M , Canedo LM , Prieto MA , Garcia JL , Martinez M , Luengo JM
Ref : Journal of Biological Chemistry , 274 :29228 , 1999
Abstract : Novel biodegradable bacterial plastics, made up of units of 3-hydroxy-n-phenylalkanoic acids, are accumulated intracellularly by Pseudomonas putida U due to the existence in this bacterium of (i) an acyl-CoA synthetase (encoded by the fadD gene) that activates the aryl-precursors; (ii) a beta-oxidation pathway that affords 3-OH-aryl-CoAs, and (iii) a polymerization-depolymerization system (encoded in the pha locus) integrated by two polymerases (PhaC1 and PhaC2) and a depolymerase (PhaZ). The complete assimilation of these compounds requires two additional routes that specifically catabolize the phenylacetyl-CoA or the benzoyl-CoA generated from these polyesters through beta-oxidation. Genetic studies have allowed the cloning, sequencing, and disruption of the genes included in the pha locus (phaC1, phaC2, and phaZ) as well as those related to the biosynthesis of precursors (fadD) or to the catabolism of their derivatives (acuA, fadA, and paa genes). Additional experiments showed that the blockade of either fadD or phaC1 hindered the synthesis and accumulation of plastic polymers. Disruption of phaC2 reduced the quantity of stored polymers by two-thirds. The blockade of phaZ hampered the mobilization of the polymer and decreased its production. Mutations in the paa genes, encoding the phenylacetic acid catabolic enzymes, did not affect the synthesis or catabolism of polymers containing either 3-hydroxyaliphatic acids or 3-hydroxy-n-phenylalkanoic acids with an odd number of carbon atoms as monomers, whereas the production of polyesters containing units of 3-hydroxy-n-phenylalkanoic acids with an even number of carbon atoms was greatly reduced in these bacteria. Yield-improving studies revealed that mutants defective in the glyoxylic acid cycle (isocitrate lyase(-)) or in the beta-oxidation pathway (fadA), stored a higher amount of plastic polymers (1.4- and 2-fold, respectively), suggesting that genetic manipulation of these pathways could be useful for isolating overproducer strains. The analysis of the organization and function of the pha locus and its relationship with the core of the phenylacetyl-CoA catabolon is reported and discussed.
ESTHER : Garcia_1999_J.Biol.Chem_274_29228
PubMedSearch : Garcia_1999_J.Biol.Chem_274_29228
PubMedID: 10506180
Gene_locus related to this paper: psepu-PHAC1 , psepu-PHAC2 , psepu-PHAZ

Title : The mutation Gly142-->\;Glu in human lipoprotein lipase produces a missorted protein that is diverted to lysosomes - Busca_1996_J.Biol.Chem_271_2139
Author(s) : Busca R , Martinez M , Vilella E , Pognonec P , Deeb S , Auwerx J , Reina M , Vilaro S
Ref : Journal of Biological Chemistry , 271 :2139 , 1996
Abstract : While the molecular characterization of lipoprotein lipase (LPL) activation is progressing, the intracellular processing, transport, and secretion signals of LPL are still poorly known. The aim of this paper is to study are involvement of glycine 142 in LPL secretion and to elucidate the intracellular destination of the altered protein that remains inside the cell. We mutated the human LPL cDNA by site-directed mutagenesis in order to produce the G142e hLPL in which the glycine 142 was replaced by a glutamic acid. The wild type human LPL (WT hLPL) and the mutant G142E hLPL were expressed by transient transfection in COS1 cells. Using Western blot assays we identified a single band that had the same molecular weight for both proteins. However, Western blots of culture media did not reveal any specific band for the mutant protein, and ELISA experiments showed that the extracellular mass of the mutant LPL was only 25% of the WT protein, indicating defective secretion of the altered enzyme. Heparin increased LPL secretion in the case of the WT hLPL but did not have any stimulatory effect when acting on G142E hLPL-transfected cells. However, heparin-Sepharose chromatography revealed that both proteins presented the same heparin affinity. Metabolic labeling and radioimmunoprecipitation studies showed that both the WT and the mutant hLPL intracellular levels decreased upon chase time. Furthermore, leupeptin had a greater effect on the intracellular level of the mutant enzyme, thus indicating its higher intracellular degradation. Immunofluorescent studies using confocal microscopy indicated high colocalization of the LPL labeling and the Lamp1 lysosomal labeling in G142E hLPL-expressing cells. This result was confirmed using immunoelectron microscopy, which in addition showed gold labeling in Golgi stacks. This finding together with experiments performed with endoglycosidase H digestion of immunoprecipitated radiolabeled LPL, indicated that the mutant enzyme entered the Golgi compartment. The results reported in this paper show that the G142E hLPL is not efficiently secreted to the extracellular medium, but it is missorted to lysosomes for intracellular degradation. This finding suggests that lysosomal missorting might be a mechanism of cell quality control of secreted LPL.
ESTHER : Busca_1996_J.Biol.Chem_271_2139
PubMedSearch : Busca_1996_J.Biol.Chem_271_2139
PubMedID: 8567671
Gene_locus related to this paper: human-LPL

Title : [Serum butyrylcholinesterase variants in eastern Santiago population] - Acuna_1996_Rev.Med.Chil_124_1045
Author(s) : Acuna M , Martinez M
Ref : Rev Med Chil , 124 :1045 , 1996
Abstract : BACKGROUND: Succinylcholine causes prolonged apneas in a proportion if subjects that have genetical defect of butyrylcholinesterase, due to the presence of unusual alleles in the locus BCHE. AIM: To estimate allele frequencies of three variants of serum butyrylcholinesterase, BCHE*U, BCHE*A and BCHE*F in an urban population of Santiago, Chile. SUBJECTS AND METHODS: Different phenotypes for the locus BCHE were determined in 300 blood samples coming from patients of a private clinical laboratory. The population was formed by an admixture of Amerindian and European (mostly Spanish) people. RESULTS: The frequency of BCHE*A was similar to that expected for this population, but BCHE*F frequency was greater than predicted. Eight subjects had the genotype BCHE AK.
CONCLUSIONS: The higher frequency found for BCHE*F is probably due to the use of more precise detection techniques. Although the used method cannot distinguish BCHE UK from BCHE UU, the finding of individuals with BCHE AK, must lead to the suspicion that the frequency of the allele BCHE K is not negligible in Santiago.
ESTHER : Acuna_1996_Rev.Med.Chil_124_1045
PubMedSearch : Acuna_1996_Rev.Med.Chil_124_1045
PubMedID: 9197017

Title : Genetic linkage mapping of the m4 human muscarinic receptor (CHRM4) -
Author(s) : Grewal RP , Martinez M , Hoehe M , Bonner TI , Gershon ES , Detera-Wadleigh S
Ref : Genomics , 13 :239 , 1992
PubMedID: 1577490