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1.
Cuad. med. forense ; 16(1/2): 65-79, ene.-jun. 2010. ilus
Artigo em Espanhol | IBECS | ID: ibc-94650

RESUMO

La antropología forense tiene por objeto tanto la identificación del individuo, como la determinación de la causa y circunstancias de la muerte. En este sentido, la antropología forense es esencial para la recuperación de los restos de personas desaparecidas y que fueron enterrados en fosas comunes durante la Guerra Civil y la dictadura franquista, para su posterior retorno a los familiares. En este trabajo se presentan los resultados de la intervención llevada a cabo en la fosa de Gurb, en la que fueron enterrados cuatro soldados republicanos vecinos de Gavà y cuyos familiares habían solicitado su exhumación. El trabajo multidisciplinar llevado a cabo permitió: 1) recuperar toda la información ante mortem disponible en relación a la fosa y los desaparecidos, 2) recuperar mediante metodología arqueológica y directrices antropológico-forenses los restos de los 13 individuos enterrados en la fosa, y 3) analizar los restos en el laboratorio a través de técnicas antropológicas, forenses, moleculares y de superposición craneofacial. Los resultados permitieron tanto la identificación de las cuatro personas buscadas, como la determinación de las causas y circunstancias de su muerte, relacionadas todas ellas con heridas por arma de fuego, acaecidas en un contexto de batalla (AU)


Forensic Anthropology seeks both to identify the individual, such as determining the cause and circumstances of death. In this sense, forensic anthropology is essential for recovery remains of missing persons who were buried in mass graves during the Spanish Civil War and Franco's dictatorship, for subsequent return to their families. This paper presents the results of work done at the grave of Gurb, where Republican soldiers were buried; four families of Gavà had applied for exhumation of their relatives buried in it. The multidisciplinary work carried out allowed us: 1) to retrieve all available ante mortem information regarding the pit and the missing persons, 2) to recover the remains of 13 individuals buried in the grave by archaeological methods and forensic-anthropological guidelines, and 3) to analyze their remains in the laboratory through anthropological, forensics, molecular and craniofacial superimposition techniques. The results allowed both the identification of the four wanted persons, such as determining the causes and circumstances of his death, in all cases due to battle related trauma, specifically firearm injuries (AU)


Assuntos
Humanos , Antropologia Forense/tendências , Identificação de Vítimas , Impressões Digitais de DNA , Causas de Morte , Ferimentos por Arma de Fogo/diagnóstico , Cemitérios , Guerra , Vítimas de Crime
2.
Cuad. med. forense ; 13(48/49): 179-189, abr.-jun. 2007. ilus, tab
Artigo em Es | IBECS | ID: ibc-058411

RESUMO

Los marcadores de actividad se definen como cambios de la arquitectura interna y/o externa del hueso, que se desarrollan bajo condiciones de estrés continuado y prolongado derivado de la realización de actividades habituales u ocupacionales. Las evidencias obtenidas a partir de estas marcas esqueléticas constituyen una valiosa fuente de información que permite generar hipótesis sobre determinados antecedentes de la vida de un sujeto, útiles en la individualización de unos restos esqueléticos. Por tanto, el análisis de estos marcadores debe ser considerado como una fase más del proceso de necroidentificación forense


Activity markers are defined as observable changes in the internal and/or external bone architecture which develop under conditions of prolonged and continued stress imposed by habitual or occupational activity. The evidences obtained from these markers are very important information which allows us to make hypothesis about certain aspects of the subject’s life, useful when it comes to individualize skeletal remains. Therefore, the analysis of these markers should be considered as an additional step in the forensic necroidentification


Assuntos
Masculino , Feminino , Humanos , Antropologia Forense/métodos , Biomarcadores/análise , Osso e Ossos/anatomia & histologia , Osso e Ossos/citologia , Osso e Ossos/ultraestrutura , Paleopatologia/métodos , Desgaste dos Dentes/etiologia , Antropologia Forense/classificação , Antropologia Forense/estatística & dados numéricos , Antropologia Forense/tendências , Osteogênese , Ossificação Heterotópica/diagnóstico , Ossificação Heterotópica/etiologia
3.
Cuad. med. forense ; 11(42): 293-305, oct. 2005. ilus
Artigo em Es | IBECS | ID: ibc-048994

RESUMO

La identificación de un cadáver en "mal estado" puede ser complicada a causa de los procesos tafonómicos y putrefactivos que ha sufrido. La combinación de las técnicas de autopsia clásicas, específicas de un cadáver reciente, además de los análisis en antropología forense son fundamentales para determinar el tipo de lesiones, mecanismo de producción, evolución y, como en este caso, para la calificación jurídica. Presentamos el caso de un cadáver no identificado y parcialmente incinerado aparecido en un descampado. El examen externo evidenció la coexistencia de zonas de carbonización, momificación, reducción esquelética y descomposición activa. La autopsia reveló la existencia de puntos de sutura a nivel abdominal como signos individualizadores y como signos de violencia un traumatismo craneoencefálico múltiple. Los restos fueron esqueletizados y se efectuó un estudio antropológico y odontológico. A partir de estos análisis se obtuvo información sobre la edad, sexo, talla además de rasgos morfológicos y odontológicos particulares. Estos hallazgos, además de los proporcionados por la autopsia, se contrastaron con la información de la policía sobre individuos desaparecidos y finalmente pudo identificarse. El patrón de fractura craneal permitió secuenciar el orden de las lesiones que fueron atribuidos a la acción repetitiva de un objeto contundente como un martillo. La cronología lesional, basada en el patrón de interrupción de las fracturas craneales irradiadas, permitió asegurar que el primer impacto del martillo fue en la zona posterior del cráneo y sirvió de base para la calificación de traición como agravante de la pena solicitada por el Ministerio Fiscal para el homicida


Identification of a corpse in a bad condition can be complicated due to taphonomical processes and active decomposition on human remains. The combination of classical autopsy techniques, characteristic of the study of a recent corpse, and legal anthropology analysis, is fundamental in order to determine the type of lesions, the mechanism, its evolution and, as in this case, to allow a juridical qualification. In this paper we describe the case of an unidentified corpse, partially burned that appeared in the open air in a waste area. External examination showed the coexistence of carbonization, mummification, skeletal reduction and active decomposition zones. Autopsy showed the existence of stitches at abdominal level as an individual trait and, as signs of violence, a multiple craneal traumatism. A skeleton has been made with the human remains and an anthropological and odontological study was carried out. Starting from these analysis we obtained information about the age, sex, height and also peculiar morphological and odontological traits. These researches, in the light of the autopsy's results, have been compared with the information about missing people supplied by police. Finally, the identification was possible. The pattern of the skull's fracture allowed to arrange in sequence the lesions and to consider them to the repeated action of a blunt instrument such as a hammer. The chronology of the lesions, based on the pattern of interruption of irradiated fractures, permit to assure that the first hammer's blow was made on the cráneoum's rear. This has been qualified as a treacherous act and increased the murderer's penalty requested by the public attorney


Assuntos
Masculino , Adulto , Humanos , Antropologia Forense/métodos , Morte , Cadáver , Traumatismos Craniocerebrais/diagnóstico , Traumatismos Craniocerebrais/mortalidade , Homicídio/ética , Autopsia/legislação & jurisprudência , Autopsia/métodos , Determinação da Idade pelo Esqueleto/métodos , Causas de Morte , Antropologia Forense/ética , Antropologia Forense/instrumentação , Antropologia Forense/tendências , Radiografia Torácica/ética , Radiografia Torácica/métodos , Radiografia Abdominal/métodos , Radiografia Abdominal
4.
Dentomaxillofac Radiol ; 33(4): 278-81, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15533986

RESUMO

In this paper, an archaeological case of unilateral bifid mandibular condyle is presented. This uncommon anomaly is characterized by a division of the mandibular condylar head. In this case, the left condyle was divided into two articulating surfaces oriented mediolaterally; two articular facets on the anterior wall of the glenoid fossa for the double condyle were observed. The morphological and radiological analysis do not show any evidence of injuries or degenerative pathology. Taking into account the two main causes of bifid condyle suggested in the literature (traumatic and developmental), an embryopathy by teratogenic agents is proposed as a possible aetiology of the bifid condyle reported here.


Assuntos
Côndilo Mandibular/anormalidades , Paleopatologia , História Antiga , Humanos , Masculino , Côndilo Mandibular/patologia , Espanha
5.
Mol Cell Biol ; 21(20): 6731-7, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11564858

RESUMO

RNA editing in higher plant mitochondria modifies mRNA sequences by means of C-to-U conversions at highly specific sites. To determine the cis elements involved in recognition of an editing site in plant mitochondria, deletion and site-directed mutation constructs containing the cognate cox II mitochondrial gene were introduced into purified mitochondria by electroporation. The RNA editing status was analyzed for precursor and spliced transcripts from the test construct. We found that only a restricted number of nucleotides in the vicinity of the target C residue were necessary for recognition by the editing machinery and that the nearest neighbor 3' residues were crucial for the editing process. We provide evidence that two functionally distinguishable sequences can be defined: the 16-nucleotide 5' region, which can be replaced with the same region from another editing site, and a 6-nucleotide 3' region specific to the editing site. The latter region may play a role in positioning the actual editing residue.


Assuntos
Mitocôndrias/metabolismo , Proteínas de Plantas/metabolismo , Edição de RNA , RNA Mensageiro/metabolismo , Apoproteínas/genética , Sequência de Bases , Sítios de Ligação , Grupo dos Citocromos b/genética , Citocromos b , Eletroporação , Deleção de Genes , Modelos Genéticos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas de Plantas/genética , Plasmídeos/metabolismo , Mutação Puntual , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
6.
Plant Mol Biol ; 46(2): 241-50, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11442063

RESUMO

The iron-sulfur protein is an essential component of mitochondrial complex II (succinate dehydrogenase, SDH), which is a functional enzyme of both the citric acid cycle and the respiratory electron transport chain. This protein is encoded by a single-copy nuclear gene in mammals and fungi and by a mitochondrial gene in Rhodophyta and the protist Reclinomonas americana. In Arabidopsis thaliana, the homologous protein is now found to be encoded by three nuclear genes. Two genes (sdh2-1 and sdh2-2) likely arose from a relatively recent duplication event since they have similar structures, encode nearly identical proteins and show similar expression patterns. Both genes are interrupted by a single intron located at a conserved position. Expression was detected in all tissues analysed, with the highest steady-state mRNA levels found in flowers and inflorescences. In contrast, the third gene (sdh2-3) is interrupted by 4 introns, is expressed at a low level, and encodes a SDH2-3 protein which is only 67% similar to SDH2-1 and SDH2-2 and has a different N-terminal presequence. Interestingly, the proteins encoded by these three genes are probably functional because they are highly conserved compared with their homologues in other organisms. These proteins contain the cysteine motifs involved in binding the three iron-sulfur clusters essential for electron transport. Furthermore, the three polypeptides are found to be imported into isolated plant mitochondria.


Assuntos
Arabidopsis/genética , Proteínas Ferro-Enxofre/genética , Succinato Desidrogenase/genética , Sequência de Aminoácidos , Arabidopsis/enzimologia , Sequência de Bases , Núcleo Celular/genética , Primers do DNA , DNA Complementar , Éxons , Genes de Plantas , Íntrons , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Succinato Desidrogenase/química
7.
Plant Physiol ; 125(1): 396-405, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11154347

RESUMO

Salicylic acid (SA) activates immediate early transcription of genes controlled by a family of DNA promoter elements named as-1-like elements. These elements are functional in the promoter of glutathione S-transferase genes. We have previously shown that SA increases the binding of tobacco (Nicotiana tabacum cv Xanthi nc) nuclear factors to the as-1 sequence in a process mediated by protein phosphorylation. In this study we give evidence for the participation of a nuclear protein kinase CK2 (casein kinase 2) in the pathway activated by SA in tobacco. The first line of evidence comes from the evaluation of the CK2 activity in nuclear extracts prepared from tobacco plants treated with SA or water as a control. Results from these experiments indicate that SA increases the nuclear CK2 activity. The second line of evidence derives from the evaluation of the in vivo effect of 5,6-dichloro-1-(beta-D-ribofuranosyl) benzimidazole (DRB), a cell-permeable CK2 inhibitor, on the responsiveness of the as-1 sequence to SA. Results from these experiments indicate that DRB impairs the activating effect of SA on the transcription of both, the GUS reporter gene controlled by a tetramer of the as-1 element, and the endogenous gnt35 gene encoding a glutathione S-transferase, in transgenic tobacco plants. DRB also impaired the increasing effect of SA on the binding of nuclear factors to the as-1 element. Furthermore, transcription of the as-1/GUS reporter gene activated by the synthetic auxin 2,4-dichlorophenoxyacetic acid and by methyl jasmonate was also inhibited by DRB. To our knowledge, this is the first report in which activation of a CK2 enzyme by a plant hormone is reported.


Assuntos
Núcleo Celular/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Ácido Salicílico/farmacologia , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Caseína Quinase II , Primers do DNA , Glucuronidase/genética , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Folhas de Planta/enzimologia , Proteínas Serina-Treonina Quinases/química , /genética , Ativação Transcricional
8.
Mol Cell Biochem ; 227(1-2): 129-35, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11827163

RESUMO

We have previously reported the participation of the protein kinase CK2 in the mechanism by which salicylic acid activates transcription of genes, such as those coding for glutathion S-transferases, in tobacco. With the purpose of further studying the participation of CK2 in this signal transduction pathway, we isolated and sequenced the cDNA from the NtCK2A gene, coding for the catalytic alpha subunit of CK2 from tobacco. The NtCK2A cDNA was isolated by screening of a tobacco cDNA library with a heterologous probe from Arabidopsis thaliana, followed by 3' RACE to obtain the 3' region. Sequence analysis of the NtCK2A cDNA showed a high level of identity between this CK2alpha protein sequence and the corresponding sequences of other plant species such as Arabidopsis and maize (92-95% identity), or those of animal species such as human and Xenopus laevis (75% identity). The expression of the NtCK2A gene in different tissues from tobacco plants was analyzed by Northern blot. High levels of expression of this gene were observed in proliferating tissues such as shoot and root apical meristems. A recombinant CK2alpha protein was obtained after expression of the NtCK2A cDNA in Escherichia coli. The ability of this recombinant CK2alpha subunit to phosphorylate casein was inhibited by heparin and stimulated by the CK2beta subunit from Xenopus laevis.


Assuntos
/enzimologia , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Animais , Arabidopsis/enzimologia , Sequência de Bases , Northern Blotting , Western Blotting , Caseína Quinase II , Clonagem Molecular , DNA/metabolismo , DNA Complementar/metabolismo , Escherichia coli/metabolismo , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Distribuição Tecidual , Xenopus , Xenopus laevis , Zea mays/enzimologia
9.
Mol Gen Genet ; 263(4): 733-9, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10852496

RESUMO

Mitochondrial ribosomal protein S10 (rps10) is encoded by the mitochondrial genome in potato and pea. Here we show that the rps10 gene is absent from the mitochondrial genome of rice and has been transferred to the nucleus. Cloning and transcriptional analysis show that there are two rps10 genes in the rice nuclear genome and that their transcripts differ in abundance. Western analysis detected the RPS10 protein in the soluble fraction of rice mitochondria, although neither RPS10 has any obvious N-terminal presequence for targeting to mitochondria. This result suggests that targeting information is present in the internal region of rice RPS10. Genomic sequence analysis indicated that each rps10 gene has an intron in the 5' untranslated region (5' UTR) and that these intron sequences are homologous to each other. This result strongly suggests that a duplication event occurred after transfer of the rps10 gene to the nucleus. The duplicated rps10 genes have since been translocated to different chromosomes, because the two rps10 genes were mapped on chromosomes 6 and 12 by RFLP analysis. Interestingly, the 5' UTR and the intron of the rice rps10 genes are homologous to sequences found in several rice genes with various functions, such as osk4, EF-1beta2 and RAG1, suggesting a common origin and a functional role for the 5' UTR. Acquisition of the 5' flanking region might have accelerated the activation of the mitochondrial rps10 gene which was transferred to the nuclear genome.


Assuntos
Regiões 5' não Traduzidas/genética , Núcleo Celular/genética , Duplicação Gênica , Mitocôndrias/genética , Oryza/genética , Polimorfismo de Fragmento de Restrição , Proteínas Ribossômicas/genética , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Biblioteca Gênica , Técnicas de Transferência de Genes , Dados de Sequência Molecular , Oryza/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
10.
Biochem Biophys Res Commun ; 271(2): 380-5, 2000 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-10799306

RESUMO

In maize, the functional gene encoding mitochondrial ribosomal protein S14 (rps14) has been translocated to the nucleus where it became integrated between both exons of a gene encoding the iron-sulfur subunit of succinate dehydrogenase (sdh2). Two transcripts are generated from this locus by alternative splicing. One transcript encodes a precursor for a functional SDH2 protein, while the second transcript encodes a chimeric SDH2(t)-RPS14 precursor protein. In this paper we show that the same mitochondrial targeting presequence is able to direct the import of both precursors into isolated mitochondria and is removed during import. This processing event generates a 28 kDa protein from the SDH2 precursor, which corresponds to the iron-sulfur subunit of respiratory complex II present in maize mitochondria. In addition to cleavage of the presequence, the chimeric precursor undergoes proteolytical processing between SDH2 and RPS14. This processing generates RPS14, which is found assembled into mitochondrial ribosomes, and a truncated SDH2 protein which is degraded. Therefore, our results support a role of the SDH2 domain in the chimeric precursor only in providing a mitochondrial targeting function for RPS14.


Assuntos
Mitocôndrias/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Ribossômicas/metabolismo , Succinato Desidrogenase/metabolismo , Zea mays/metabolismo , Sequência de Aminoácidos , Núcleo Celular/metabolismo , DNA Complementar/metabolismo , Eletroforese em Gel de Poliacrilamida , Éxons , Immunoblotting , Modelos Genéticos , Dados de Sequência Molecular , Oryza/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Ribossômicas/genética , Homologia de Sequência de Aminoácidos , Succinato Desidrogenase/genética
11.
Mol Gen Genet ; 262(1): 139-44, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10503545

RESUMO

The transfer of genetic information from the mitochondrion to the nucleus is thought to be still underway in higher plants. The mitochondrial genome of Arabidopsis thaliana contains only one rps14 pseudogene. In this paper we show that the functional gene encoding mitochondrial ribosomal protein S14 has been translocated to the nucleus. This gene transfer is a recent evolutionary event, which occurred within Cruciferae, probably after the divergence of Arabidopsis and Brassica napus. A 5' extension of the rps14 reading frame encodes a presequence which, in vitro, targets the polypeptide to isolated mitochondria and is cleaved off during or after import. No intron was found at the junction of the targeting presequence with the mitochondrially derived sequence, which are directly connected. By contrast, a 90-bp intron, which is removed by splicing to give a mature poly(A)+ mRNA of 0.9 kb, is located in the 3' non-coding region. To our knowledge, this is the first report of an intron in such a position in a functional transferred gene in higher plants, and suggests that exon shuffling may have been involved in the acquisition of elements necessary for expression in the nucleus. Putative roles of this intron in polyadenylation and enhancement of gene expression are discussed.


Assuntos
Arabidopsis/genética , Núcleo Celular/genética , Genes de Plantas , Mitocôndrias/química , Proteínas Ribossômicas/genética , Sequência de Aminoácidos , Sequência de Bases , Transporte Biológico , Compartimento Celular , Éxons , Íntrons , Dados de Sequência Molecular , Sinais Direcionadores de Proteínas , Processamento Pós-Transcricional do RNA , RNA Mensageiro , Sequências Reguladoras de Ácido Nucleico , Proteínas Ribossômicas/metabolismo , Homologia de Sequência de Aminoácidos
12.
Plant J ; 18(6): 601-9, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10417711

RESUMO

The maize mitochondrial genome does not contain a gene coding for ribosomal protein S14. In this paper we show that the functional rps14 gene was translocated to the nucleus and acquired the signals conferring expression and product targeting to the mitochondrion in a way not previously described. Transferred rps14 was found integrated between both exons of a gene encoding the iron-sulphur subunit of the respiratory complex II (sdh2). Sdh2 exon 1 and rps14 were separated by a typical plant nuclear intron that was spliced to give a mature poly(A)+ mRNA of 1.4 kb. This processed mRNA encoded a chimeric SDH2 (truncated)-RPS14 polypeptide, and we show that this chimeric polypeptide is targeted into isolated plant mitochondria, where it is proteolytically processed in a complex way. An alternative splicing event utilizing the same 5' splice site and a different downstream 3' splice site generated a second mature poly(A)+ mRNA of 1.3 kb that contained both sdh2 exons. This sdh2 transcript encoded an SDH2 polypeptide highly conserved compared with its homologues in other organisms, and it contained the three cysteine-rich clusters that made up the three non-heme iron-sulphur centres responsible for electron transport. To our knowledge, these results constitute the first evidence of alternative splicing playing a role in the expression and targeting of two mitochondrial proteins with different functions from the same gene.


Assuntos
Processamento Alternativo , Núcleo Celular/metabolismo , Proteínas Ferro-Enxofre/genética , Mitocôndrias/metabolismo , Proteínas Ribossômicas/metabolismo , Zea mays/genética , Sequência de Aminoácidos , Sequência de Bases , Transporte Biológico , Primers do DNA , Dados de Sequência Molecular , RNA Mensageiro/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Ribossômicas/genética , Homologia de Sequência de Aminoácidos , Succinato Desidrogenase/genética , Zea mays/enzimologia
13.
Curr Genet ; 33(6): 420-8, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9644205

RESUMO

The intronic mat-r ORF encodes a protein with significant homology to retroviral reverse transcriptases. Here, we describe the nucleotide sequence of potato mat-r and study the editing status of mat-r transcripts in two systems, potato and wheat, where the mat-r ORF is part of the trans-introns but in two different configurations relative to nad1 exons d and e. In potato and wheat, 13 and 15 C-to-U transitions respectively were observed. Most transcripts were partially edited, but potato transcripts were edited more efficiently than wheat transcripts. As in functional mitochondrial genes, RNA editing increased the similarity between plant mat-r proteins and their homologous non-plant counterparts. Interestingly, editing of mat-r was clustered in the reverse-transcriptase (RT) and the maturase (X) domains, two well defined regions having known functions in other systems. These results, together with the integrity and sequence conservation of mat-r, strongly suggest that the encoded protein plays a functional role in plant mitochondria.


Assuntos
Endorribonucleases/genética , Mitocôndrias/genética , Nucleotidiltransferases/genética , Proteínas de Plantas/genética , Edição de RNA/genética , Solanum tuberosum/genética , Triticum/genética , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação/genética , Sítios de Ligação/fisiologia , Citidina/genética , Citidina/metabolismo , Citosina/metabolismo , DNA Mitocondrial/análise , DNA Mitocondrial/genética , DNA de Plantas/análise , DNA de Plantas/genética , Endorribonucleases/isolamento & purificação , Genes de Plantas/genética , Mitocôndrias/química , Dados de Sequência Molecular , Nucleotidiltransferases/isolamento & purificação , RNA/genética , RNA/metabolismo , RNA Mitocondrial , DNA Polimerase Dirigida por RNA/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Solanum tuberosum/química , Transcrição Gênica/genética , Triticum/química , Uracila/metabolismo , Uridina/genética , Uridina/metabolismo
14.
Plant J ; 11(6): 1315-24, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9225470

RESUMO

The cis-located DNA sequence as-1 (Activation Sequence-1) from CaMV 35S promoter has been previously identified as an element that can confer inducibility by salicylic acid (SA) with immediate early kinetics. This sequence specifically binds to ASF-1 (Activation Sequence Factor-1), previously characterized in tobacco nuclear extracts. To assess whether modulation of ASF-1 binding activity can explain the activation of the as-1 sequence observed in vivo, we performed electrophoretic mobility shift assays using nuclear extracts from SA-treated and water-treated tobacco plants. Our results indicate that treatment of plants with SA increases ASF-1 binding to as-1 and to ocs, an as-1-like element from the Agrobacterium octopine synthase gene. In contrast, SA treatment has no effect on the binding of GT-1 factor to its target light-inducible box II element. Furthermore, treatment of nuclear extracts from SA-treated plants with alkaline phosphatase decreases ASF-1 binding to the as-1 element. This can be reversed by pretreatment with 10 mM NaF. Accordingly, pretreatment of nuclear extracts from control water-treated plants with ATP produces an increase in ASF-1 binding activity similar to that observed with SA. This effect of ATP is reversed by treatment with alkaline phosphatase and prevented by quercetin, a casein kinase II inhibitor. These results support the hypothesis that a nuclear protein kinase is involved in the immediate early events of transcriptional activation triggered by SA.


Assuntos
Proteínas de Arabidopsis , DNA de Plantas/metabolismo , Proteínas Nucleares/metabolismo , Salicilatos/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica , Sítios de Ligação , Proteínas de Ligação a DNA/metabolismo , Fosforilação , Proteínas de Plantas/metabolismo , Plantas Tóxicas , Ácido Salicílico , Fatores de Transcrição/metabolismo , Ativação Transcricional
15.
Plant Mol Biol ; 31(4): 937-43, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8806426

RESUMO

The L5 ribosomal protein gene (rpl5) and a S14 ribosomal protein pseudogene were identified by sequence analysis in the potato mitochondrial genome. The two genes are separated by one nucleotide and are found upstream of the apocytochrome b gene (cob), an arrangement conserved also in Arabidopsis and Brassica. The rpl5 gene has an intact open reading frame while the rps14 locus is disrupted by a five nucleotide duplication that introduces a frameshift in the reading frame. Editing of rpl5 and pseudorps14 cotranscripts has been studied by cDNA sequence analysis. Eight C residues are edited into U in the rpl5 coding region, resulting in eight amino acid changes that increase the homology between potato and other RPL5 polypeptides. Interestingly, the rps14 pseudogene sequence is not edited at any nucleotide position.


Assuntos
Genes de Plantas/genética , Pseudogenes/genética , Proteínas Ribossômicas/genética , Solanum tuberosum/genética , Sequência de Aminoácidos , Apoproteínas/genética , Sequência de Bases , Grupo dos Citocromos b/genética , Citocromos b , DNA Mitocondrial/genética , DNA de Plantas/genética , Mitocôndrias , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , RNA/análise , Edição de RNA/fisiologia , RNA Mitocondrial , RNA de Plantas/análise , Mapeamento por Restrição , Análise de Sequência de DNA
16.
Plant Mol Biol ; 31(2): 365-72, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8756599

RESUMO

A reverse transcriptase activity has been detected in potato mitochondria using special RNAs as templates: a bacterial RNA coding for neomycin phosphotransferase (neo pa RNA) and a Neurospora crassa mitochondrial RNA (184 nt RNA). Surprisingly, no exogenous primer addition was required. These RNA templates share a primary and secondary structure similar to the T psi CG loop of tRNAs that could constitute the recognition site for the enzyme. Reverse transcriptase activity was inhibited by ddTTP, ethidium bromide and aphidicolin, while potato mitochondrial DNA polymerase was not inhibited by aphidicolin indicating that these activities correspond to distinct enzymes. A conserved sequence of reverse transcriptases was detected in potato mitochondrial DNA suggesting that this enzyme could be mitochondrially encoded.


Assuntos
Mitocôndrias/enzimologia , DNA Polimerase Dirigida por RNA/metabolismo , Solanum tuberosum/enzimologia , Sequência de Bases , DNA Complementar/genética , DNA Mitocondrial/genética , Genes de Plantas , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oligonucleotídeos/química , RNA/ultraestrutura , RNA Mitocondrial , DNA Polimerase Dirigida por RNA/genética , Inibidores da Transcriptase Reversa/farmacologia
17.
Biochimie ; 78(6): 511-7, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8915540

RESUMO

The term 'RNA editing' was used for the first time in 1986 to describe the process of uridylate insertion into trypanosomal mitochondrial transcripts. Since then, the term has been used more generally to describe a large variety of processes involving base insertions, deletions and conversions that generate RNAs with a primary sequence different to those encoded by the gene. RNA editing has been observed in the mitochondrial fraction of trypanosomes, plants and other organisms, in the animal nuclear fraction in the case of the apolipoprotein B and glutamate brain receptors mRNAs as well as in viruses like paramyxovirus, hepatitis delta and probably HIV. The role of cytidine and adenine deamination leading to C to U and A to I transitions has became pivotal to explain this process by base conversion. In this review we will focus mainly on the work performed in our group on plant mitochondria and more specifically on the mechanism and the functional significance of RNA editing in wheat organelles. The original contributions of our laboratory in this field are: i) showing that RNA editing is reflected at the protein level; ii) settling three in vitro systems to assay C to U conversion using a wheat mitochondrial lysate as source of enzymes and factors, and unedited mRNA from the same source, as substrate; iii) determination by double labelling of the unedited substrate that RNA editing in wheat mitochondria occurs via a deamination step; and iv) that introducing unedited proteins in the mitochondria of transgenic plants leads to the emergence of cytoplasmic male sterility supporting the idea that the role of this process is to produce functional proteins. Using the antisense approach in transgenic plants we were able to obtain a significant male fertility restoration.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Mitocôndrias/metabolismo , Edição de RNA/genética , Citosina Desaminase , Desaminação , Evolução Molecular , Fertilidade/genética , Técnicas de Transferência de Genes , Nucleosídeo Desaminases/metabolismo , Plantas Geneticamente Modificadas/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Triticum/enzimologia , Triticum/metabolismo
19.
Curr Genet ; 27(6): 565-71, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7553943

RESUMO

The structure and expression of the potato mitochondrial gene rps10, encoding ribosomal protein S10, has been characterized. The RPS10 polypeptide of 129 amino acids is encoded by two exons of 307 bp and 80 bp respectively, which are separated by a 774-bp class-II intron. Editing of the complete rps10 coding region was studied by sequence analysis of spliced cDNAs. Four C residues are edited into U, resulting in the creation of a putative translational initiation codon, a new stop codon which eliminated ten carboxy-terminal residues, and two additional amino-acid alterations. All these changes increase the similarity between the potato and liverwort polypeptides. One additional C-to-U RNA editing event, observed in the intron sequence of unspliced cDNAs, improves the stability of the secondary structure in stem I (i) of domain I and may thus be required for the splicing reaction. All spliced cDNAs, and most unspliced cDNAs, were completely edited, suggesting that editing is an early step of rps10 mRNA processing and precedes splicing. Earlier work on potato rps10 (Zanlungo et al. 1994) is now known to comprise only a partial analysis of the gene, since the short downstream exon was not identified.


Assuntos
Proteínas de Plantas/genética , Edição de RNA/genética , Splicing de RNA/genética , Proteínas Ribossômicas/genética , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Códon/genética , Primers do DNA/genética , DNA Complementar/genética , DNA Mitocondrial/genética , DNA de Plantas/genética , Éxons , Genes de Plantas , Íntrons , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA de Plantas/química , RNA de Plantas/genética , RNA de Plantas/metabolismo , Homologia de Sequência de Aminoácidos , Transcrição Gênica
20.
FEBS Lett ; 349(2): 243-8, 1994 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-8050574

RESUMO

The potato mitochondrial atp9 gene has a simple expression pattern. To determine where transcription initiates, primary mitochondrial RNAs were labeled by in vitro capping and hybridized to the 5' flanking sequences of the atp9 gene. A single transcription initiation region was identified. Primer extension and nuclease S1 protection analyses were used to precisely map the transcript 5' termini in this region. These results indicate that transcription initiates at 121-128 bp upstream of the atp9 open reading frame, in a sequence which does not present any homology with proposed consensus sequences for plant mitochondrial promoters. Nuclease S1 protection were also used to map 3' termini 67-71 nucleotides downstream of a putative single-stem loop structure.


Assuntos
Adenosina Trifosfatases/genética , Mitocôndrias/metabolismo , Solanum tuberosum/genética , Transcrição Gênica , Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Sequência de Bases , Northern Blotting , Southern Blotting , DNA , Dados de Sequência Molecular , Mapeamento por Restrição , Solanum tuberosum/enzimologia , Solanum tuberosum/ultraestrutura
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