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1.
Diabet Med ; 29(4): 492-500, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21916970

RESUMEN

AIMS: Skin autofluorescence, a non-invasive measure of the accumulation for advanced glycation end products, has been reported to be a useful marker for diabetic vascular risks in the Caucasian population. The aim of this study was to evaluate associations between skin autofluorescence and vascular complications in non-Caucasian patients with Type 2 diabetes. METHODS: Subjects in this cross-sectional study comprised 130 Japanese patients with Type 2 diabetes. Skin advanced glycation end products were assessed by skin autofluorescence using an autofluorescence reader. Association between skin autofluorescence and severity of vascular complications was evaluated. RESULTS: Of the 130 patients, 60 (46.2%) had microvascular complications such as diabetic retinopathy, neuropathy and nephropathy, 10 (7.7%) had macrovascular complications and 63 (48.5%) had micro- and/or macrovascular complications. Skin autofluorescence increased with severity of vascular complications. Independent determinants of skin autofluorescence were age (ß = 0.24, P < 0.01), mean HbA(1c) in previous year (ß = 0.17, P = 0.03), microvascular complications (ß = 0.44, P < 0.01) and macrovascular complications (ß = 0.27, P < 0.01). Multiple logistic regression analysis revealed that diabetes duration (odds ratio 1.15, P < 0.01), systolic blood pressure (odds ratio 1.04, P = 0.01), skin autofluorescence (odds ratio 3.62, P = 0.01) and serum albumin (odds ratio 0.84, P < 0.01) were independent factors for the presence of vascular complications in these patients. CONCLUSIONS: Skin autofluorescence had independent effects on vascular complications in Japanese patients with Type 2 diabetes. This indicates that skin advanced glycation end products are a surrogate marker for vascular risk and a non-invasive autofluorescence reader may be a useful tool to detect high-risk cases in non-Caucasian patients with diabetes.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Diabetes Mellitus Tipo 2/complicaciones , Fluorescencia , Productos Finales de Glicación Avanzada/metabolismo , Piel/metabolismo , Fumar/efectos adversos , Anciano , Pueblo Asiatico , Presión Sanguínea , Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/metabolismo , Estudios Transversales , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/metabolismo , Angiopatías Diabéticas/epidemiología , Angiopatías Diabéticas/etiología , Angiopatías Diabéticas/metabolismo , Nefropatías Diabéticas/epidemiología , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/metabolismo , Neuropatías Diabéticas/epidemiología , Neuropatías Diabéticas/etiología , Neuropatías Diabéticas/metabolismo , Retinopatía Diabética/epidemiología , Retinopatía Diabética/etiología , Retinopatía Diabética/metabolismo , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de Riesgo
2.
Biochem Biophys Res Commun ; 275(2): 472-6, 2000 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-10964689

RESUMEN

Neurotrophins including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) are known to play important roles in the survival, proliferation, differentiation, and/or maintenance of function in several tissues including neuronal tissues. The role of neurotrophins in liver tissue, however, has not yet been clarified. In the present study, we assessed the temporal change in gene expression of neurotrophins, NGF, BDNF, and NT-3, and their receptors, low affinity neurotrophin receptor (p75NTR) and Trks A, B, and C, by RT-PCR technique in the liver of rats treated with lead nitrate (LN; 0.1 mmol/kg body weight), an inducer of liver hyperplasia. The mRNAs for NGF, BDNF with exon 4, NT-3, p75NTR, and all Trk members were detected in the LN-untreated liver. LN treatment resulted in increases in the levels of NGF, BDNF with exon 4, NT-3, p75NTR, and TrkA mRNAs and further led to expression of BDNF mRNA with exon 3. The increase in gene expression of neurotrophins and their receptors was closely correlated with those in liver weight. In this report, we propose for the first time that neurotrophins may play crucial roles in LN-induced liver hyperplasia.


Asunto(s)
Expresión Génica/efectos de los fármacos , Plomo/farmacología , Hígado/efectos de los fármacos , Factores de Crecimiento Nervioso/genética , Nitratos/farmacología , Animales , Secuencia de Bases , Cartilla de ADN , Hiperplasia , Hígado/patología , Masculino , Tamaño de los Órganos , Ratas , Ratas Sprague-Dawley , Receptores de Factor de Crecimiento Nervioso/genética
3.
J Chromatogr A ; 852(2): 475-85, 1999 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-10481985

RESUMEN

The separation and characterization of octylphenol ethoxylate surfactants were carried out by reversed-phase high-performance liquid chromatography on branched fluorinated silica gel columns. For Triton X-100, simultaneous separation of octylphenol ethoxylate oligomers, positional isomers of octylphenyl group and butylphenol ethoxylate oligomers was achieved. These oligomers were completely separated and identified by means of MS spectra. Ethoxylated oligomers are eluted in the sequence from small to large oligomers. Fifty-five oligomers of Triton X-405 could be separated by using gradient elution. To separate octylphenol ethoxylate surfactant, non-end-capped branched fluorinated silica gel columns were superior to end-capped columns. The relationship between ln k' and methanol concentration was linear, indicating that branched fluorinated silica gel columns were operating in the reversed-phase mode. As Van 't Hoff plots of capacity factor for all oligomers gave straight lines, the equilibrium of conformation for the ethylene oxide chain might lay to one side of either zigzag or meander conformers.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Glicoles de Etileno/aislamiento & purificación , Tensoactivos/aislamiento & purificación , Glicoles de Etileno/química , Flúor/química , Gel de Sílice , Dióxido de Silicio , Espectrofotometría Ultravioleta , Tensoactivos/química
4.
Brain Res Mol Brain Res ; 68(1-2): 186-9, 1999 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-10320796

RESUMEN

We have previously reported that in cultured rat vascular smooth muscle cells (VSMCs), neurotrophin-3 (NT-3) gene expression was suppressed by TPA (12-O-tetradecanoyl phorbol-13-acetate), which induces an AP-1 transcription factor. In the present study, to clarify the mechanism for TPA-mediated downregulation of NT-3 gene expression, effects of cycloheximide and dexamethasone (Dex) on the TPA-mediated downregulation were examined in VSMCs. Pretreatment with cycloheximide, an inhibitor of protein synthesis, or simultaneous treatment with Dex, an inhibitor of AP-1, suppressed the TPA-mediated downregulation of NT-3 gene expression. Furthermore, co-transfection of c-fos and c-jun expression vectors into VSMCs resulted in decrease in the NT-3 gene expression. The present findings suggest that TPA-induced AP-1 de novo synthesis causes the downregulation of NT-3 gene expression in VSMCs.


Asunto(s)
Regulación de la Expresión Génica/fisiología , Músculo Liso Vascular/efectos de los fármacos , Factores de Crecimiento Nervioso/genética , Acetato de Tetradecanoilforbol/farmacología , Animales , Células Cultivadas , Cicloheximida/farmacología , Dexametasona/farmacología , Regulación hacia Abajo , Vectores Genéticos , Músculo Liso Vascular/citología , Músculo Liso Vascular/metabolismo , Neurotrofina 3 , Inhibidores de la Síntesis de la Proteína/farmacología , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-jun/genética , Ratas , Ratas Endogámicas WKY , Factor de Transcripción AP-1/antagonistas & inhibidores , Transfección
5.
Neuroreport ; 9(16): 3675-9, 1998 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-9858378

RESUMEN

The neurotrophin-3 (NT-3) gene has previously been reported to consist of three exons including two 5' short untranslated exons and a 3' long exon encoding the entire protein, and to give rise to two classes of transcripts by alternative splicing of the 5' exons to the 3' coding exon. In the present study, we demonstrated the presence of at least four new classes of transcripts of the NT-3 gene, in addition to the two known transcripts. The present finding proposes the further complexity of the regulational mechanism for NT-3 expression.


Asunto(s)
Empalme Alternativo/fisiología , Exones/fisiología , Factores de Crecimiento Nervioso/genética , Animales , Clonación Molecular , Cartilla de ADN , Expresión Génica/fisiología , Masculino , Datos de Secuencia Molecular , Fármacos Neuroprotectores/metabolismo , Neurotrofina 3 , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas WKY , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Transcripción Genética/fisiología
6.
Biochem Biophys Res Commun ; 245(1): 284-8, 1998 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-9535823

RESUMEN

Most previous researches on neurotrophins including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) have focused on the nervous system, because their receptors are widely distributed in neuronal tissues. Recently, however, the participation of neurotrophins in inflammation and atherosclerosis has been proposed. Therefore, the gene expression of neurotrophins is now an urgent issue is to be investigated in nonneuronal tissues. Here, we evaluated the gene expression of neurotrophins and their receptors in rat cultured vascular smooth muscle cells (VSMCs) by the reverse transcriptase-polymerase chain reaction method. The transcripts of NGF, NT-3, and TrkC (high-affinity receptor for NT-3), and two BDNF alternative spliced transcript variants with exons 3 and 4 were clearly detected in VSMCs cultured under conventional culture conditions. The upregulation of mRNA levels for NGF, two BDNF variants with exons 1 and 2, low-affinity neurotrophin receptor, and high-affinity receptors, TrkA (for NGF) and TrkB (for BDNF), was observed in response to the treatment with serum and phorbol-ester following the serum-starvation. In contrast, the expression of NT-3 and TrkC genes was downregulated under these conditions. Co-expression of these factors and their receptors and the characteristic regulation of their gene transcriptions suggest that these factors play crucial roles in the function of VSMCs through an autocrine mechanism.


Asunto(s)
Regulación de la Expresión Génica/genética , Músculo Liso Vascular/efectos de los fármacos , Proteínas del Tejido Nervioso/genética , Empalme Alternativo/genética , Animales , Aorta , Factor Neurotrófico Derivado del Encéfalo/genética , Células Cultivadas , Medios de Cultivo/farmacología , Regulación hacia Abajo/fisiología , Factores de Crecimiento Nervioso/genética , Neurotrofina 3 , Reacción en Cadena de la Polimerasa , Ratas , Ratas Wistar , Proteínas Tirosina Quinasas Receptoras/genética , Receptor trkC , Receptores de Factor de Crecimiento Nervioso/genética , Acetato de Tetradecanoilforbol/farmacología
7.
Biochem Biophys Res Commun ; 229(3): 713-8, 1996 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-8954962

RESUMEN

Brain-derived neurotrophic factor and its receptor, trkB, are thought to play a crucial role for protection against neuronal death induced by brain ischemia, such as in stroke. In the present study we found a missense mutation in the trkB gene from all of the five substrains of stroke-prone spontaneously hypertensive rats (SHRSP) that were examined. This mutation was not found in six out of seven hypertensive but stroke-resistant ancestral strains (SHR) of SHRSP, nor in any of seven strains of normotensive, non-stroke-prone strains. Hippocampal neurons, which are particularly vulnerable to damage in stroke, were shown to be more susceptible to ischemic damage in SHRSP than in either SHR or normotensive, stroke-resistant controls. The association of a mutated trkB gene with the stroke-prone genotype found in this study suggests that the trkB gene merits further study as a promising candidate gene for stroke.


Asunto(s)
Trastornos Cerebrovasculares/genética , Receptores de Factor de Crecimiento Nervioso/genética , Animales , Química Encefálica , Mutación , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Receptor de Factor Neurotrófico Ciliar
8.
Gene ; 145(2): 189-96, 1994 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-8056330

RESUMEN

In rat liver, the amount of tRNA(UUGGln) (RG-2) was found to be approx. 20% of that of tRNA(CUGGln) (RG-1). The independent RG-1 and RG-2 genes were isolated from a rat genomic library together with four RG-related genes containing two to five alterations in their coding regions. Sequence analysis demonstrated that there was no difference between the internal promoter sequences of RG-1 and RG-2. However, interestingly, the transcriptional activity of RG-1 was approximately four-times higher than that of RG-2 in an in vitro transcription reaction. Replacement of the 5'-flanking sequence of RG-2 by the corresponding sequence of RG-1 or by a plasmid DNA sequence caused activation of RG-2 transcription. Gel retardation assay demonstrated that the 5'-flanking region of RG-2 contained a unique sequence specifically recognized by a nuclear protein. Taken together, these results strongly suggest that the transcriptional activity of RG-2 might be negatively regulated by the binding of a nuclear protein at a specific site in the 5'-flanking region of the gene.


Asunto(s)
Regulación de la Expresión Génica , Genes/genética , Hígado/metabolismo , ARN de Transferencia de Glutamina/genética , Transcripción Genética , Animales , Secuencia de Bases , Análisis Mutacional de ADN , Proteínas de Unión al ADN/metabolismo , Datos de Secuencia Molecular , Proteínas Nucleares/metabolismo , Conformación de Ácido Nucleico , Regiones Promotoras Genéticas/genética , Ratas , Homología de Secuencia de Ácido Nucleico
9.
Arch Gerontol Geriatr ; 19 Suppl 1: 257-63, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-18649866

RESUMEN

The effect of aging on expression of a natural glutamine suppressor tRNA (tRNA(Gln(UmUG))) was studied in different tissues of mice; this tRNA recognizes UAG and inserts glutamine at the site of the termination codon. The level of tRNA(Gln(UmUG)) was found to be strongly increased in aged mice, compared to newborn and mature animals. An elevated expression of tRNA(Gln(UmUG)) has also been found in retrovirus-infected cells; in Moloney virus-infected cells the suppressor tRNA allows to read-through the UAG codon within the retroviral protease gene. We suggest that the increase in the level of tRNA(Gln(UmUG)) may influence retroviral gene expression with age.

10.
Nucleic Acids Res ; 20(13): 3463-9, 1992 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-1630916

RESUMEN

The dominant +1 frameshift suppressors sufA6, sufB1 and sufB2, in Salmonella typhimurium act at runs of C and affect tRNA(Pro)1, tRNA(Pro)2 and tRNA(Pro)2, respectively. A recessive +1 frameshift suppressor, sufC, has a similar suppressor specificity (Riddle, D.L., and Roth, J.R., Mol. Biol. 66, 483 and 495, 1972). We show that sufC strains harbour two frameshift suppressors of which one, sufX201, is allelic to sufB. We cloned the sufB+ wild type allele and by recombination in vivo the mutations sufB1, sufB2 and sufX201. Determination of the DNA sequence revealed that the sufB1 and sufB2 mutations result in an extra G in the anticodon loop of the minor tRNA(Pro)2. The sufX201 mutation results in a base substitution (G43 to A43) in the anticodon stem of this tRNA. Although the sufB1 and sufB2 mutations were earlier shown to be dominant, the sufB+ wild type allele on multi copy plasmid inhibited the chromosomal sufB1, sufB2 and sufX201 mediated frameshift suppression but not that mediated by the dominant sufA6 mutation. These results are discussed in view of the possible coding specificity of these mutated tRNAs. The DNA sequence showed a potential consensus promoter sequence upstream of the structural gene for tRNA(Pro)2 and downstream a dyad symmetrical structure followed by a T cluster, a possible rho-independent termination signal. The Salmonella tRNA(Pro)2 gene is identical to the Escherichia coli counterpart reported by Komine, Y. et al. (J. Mol. Biol. 212, 579-598, 1990). While the 5' flanking sequence similarity between the two species is about 83%, the similarity of the 3' flanking sequence is only 42%. Still, the Salmonella tRNA(Pro)2 gene has a rho-independent transcriptional termination signal similar to the one present in E. coli tRNA(Pro)2 gene.


Asunto(s)
Anticodón/genética , Mutación del Sistema de Lectura/genética , ARN de Transferencia de Prolina/genética , Salmonella typhimurium/genética , Supresión Genética/genética , Bacteriófagos/genética , Secuencia de Bases , Clonación Molecular , Escherichia coli/genética , Genes Bacterianos/genética , Datos de Secuencia Molecular , Mutagénesis Insercional/genética , Conformación de Ácido Nucleico , Plásmidos/genética
11.
J Virol ; 65(11): 6376-9, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1920640

RESUMEN

Among Moloney murine leukemia viruses (Mo-MuLVs) having stop codons other than UAG at the gag-pol junction, Mo-MuLV with UAA, but not with UGA, had a replication disadvantage. Mo-MuLV with a glutamine codon (CAG) at the junction did not replicate. A revertant of this virus consisted of the original virus and a virus with a deletion of the pol region. Protease and Pr65gag encoded by their respective genomes complemented each other.


Asunto(s)
Genes gag , Genes pol , Virus de la Leucemia Murina de Moloney/genética , Células 3T3 , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Deleción Cromosómica , Codón/genética , Genoma Viral , Ratones , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Oligodesoxirribonucleótidos , Plásmidos , Regiones Promotoras Genéticas , Biosíntesis de Proteínas , Mapeo Restrictivo , Transcripción Genética , Transfección
13.
Proc Natl Acad Sci U S A ; 86(23): 9144-8, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2594755

RESUMEN

A 9-kilobase-pair clone containing a myc-related gene that we have designated s-myc was isolated from a rat genomic library. The entire nucleotide sequence of the cloned DNA was determined, showing that the s-myc gene contains an open reading frame consisting of 1287 base pairs without introns. In vitro transcription-translation analysis of s-myc indicated that this gene produces a protein of approximately 50 kDa. The amino acid sequence predicted from the DNA sequence showed that the s-Myc protein is closely related to the murine N-Myc protein but lacks an acidic amino acid-rich sequence commonly present in the Myc-family proteins. Studies on transfection of s-myc into rat RT4-AC tumor cells revealed that the gene produces a polyadenylylated transcript of approximately 4.7 kilobases and that its high-level expression suppresses the tumor-igenicity of RT4-AC tumor cells in nude mice.


Asunto(s)
ADN de Neoplasias/genética , Familia de Multigenes , Proteínas Nucleares/genética , Fosfoproteínas/genética , Proto-Oncogenes , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Clonación Molecular/métodos , ADN de Neoplasias/aislamiento & purificación , Biblioteca Genómica , Ratones , Datos de Secuencia Molecular , Plásmidos , Biosíntesis de Proteínas , Ratas , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico , Transcripción Genética , Transfección
14.
Nihon Hotetsu Shika Gakkai Zasshi ; 33(5): 1194-201, 1989 Oct.
Artículo en Japonés | MEDLINE | ID: mdl-2489765

RESUMEN

The purpose of this study is to investigate the relationship between gingival discoloration and Ag2S. Minute granules of dental alloys were embedded in the gingiva during a 5-11 months span, and their histological and colorimetric analyses were undertaken. Results showed the following; 1. Cases of low melting silver alloy, 12% Au-Ag-Pd alloy, and Ni-Cr alloy all resulted in gingival discoloration, but it did not occur during the specified experimental period. 2. Regardless of the size of the granules or time, the electron microanalyser showed no signs of sulfer detection in cases of low melting silver alloy. However, in the case of 12% Au-Ag-Pd alloy, sulfer was detected 5 months later for only those granules having the size of 0.2-0.3 microns. No sulfer was detected in cases of Ni-Cr alloy. 3. Although no proliferation of inflammatory cells were observed around those areas surrounding the 12% Au-Ag-Pd alloy granules, they appeared in cases of the low melting silver alloy and Ni-Cr alloy.


Asunto(s)
Aleaciones Dentales/efectos adversos , Encía/patología , Trastornos de la Pigmentación/inducido químicamente , Aleaciones de Oro , Paladio , Plata/efectos adversos
15.
Nucleic Acids Res ; 17(15): 5933-45, 1989 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-2549503

RESUMEN

By carrying out oligonucleotide-directed mutagenesis, in vitro, on a 3.3 kb XhoI-HindIII fragment from Moloney murine leukaemia virus Mo-MuLV proviral DNA, inserted into the phagemid pTZ19R, nine separate fragments have been prepared in which mutations have been inserted at and around the gag-pol gene junction. Using these mutant fragments Mo-MuLV proviral DNA has been reassembled and cloned into pBR322. Examination of the mutant proviral DNAs in mouse culture cells indicates that a terminator codon at the gag-pol junction is essential for function, but any of the three chain terminator codons gives an active virus. Also the region of secondary structure surrounding the terminator codon must be preserved.


Asunto(s)
ADN Viral/genética , Virus de la Leucemia Murina de Moloney/genética , Proteínas de los Retroviridae/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Clonación Molecular , Análisis Mutacional de ADN , Enzimas de Restricción del ADN , Productos del Gen gag , Ratones , Datos de Secuencia Molecular , Mutación , Conformación de Ácido Nucleico , Oligonucleótidos/genética , Plásmidos , Transfección , Transformación Genética
16.
J Comp Pathol ; 101(2): 151-9, 1989 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2551939

RESUMEN

Reactivation of pseudorabies virus (PRV) was induced in pigs by prednisolone treatment. The virus was re-isolated from nasal secretions of four, brain cortex of two and mandibular lymph node of three out of 12 pigs, respectively. The characteristic lesion of recurrently infected pigs was focal necrosis in the brain cortex and mandibular lymph node, accompanied by reactivating virus particles in the degenerating cells. Coincident with the pathological lesions, PRV antigen was detected in two of the brain cortex and six of the mandibular lymph node specimens by immunoperoxidase staining. These results suggest that the immunoperoxidase technique was more sensitive than virus isolation for demonstrating the reactivity of PRV in recurrently infected pigs.


Asunto(s)
Antígenos Virales/análisis , Corteza Cerebral/microbiología , Ganglios Linfáticos/microbiología , Seudorrabia/microbiología , Enfermedades de los Porcinos/microbiología , Animales , Corteza Cerebral/inmunología , Corteza Cerebral/patología , Herpesvirus Suido 1/inmunología , Herpesvirus Suido 1/aislamiento & purificación , Herpesvirus Suido 1/fisiología , Técnicas para Inmunoenzimas , Ganglios Linfáticos/patología , Microscopía Electrónica , Mucosa Nasal/metabolismo , Mucosa Nasal/microbiología , Prednisolona/farmacología , Seudorrabia/patología , Recurrencia , Porcinos , Enfermedades de los Porcinos/patología
17.
Nature ; 336(6195): 179-81, 1988 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-3054566

RESUMEN

An Escherichia coli isoleucine transfer RNA specific for the codon AUA (tRNA(2Ile) or tRNA(minorIle] has a novel modified nucleoside, lysidine in the first position of the anticodon (position 34), which is essential for the specific recognition of the codon AUA. We isolated the gene for tRNA(2Ile) (ileX) and found that the anticodon is CAT, which is characteristic of the methionine tRNA gene. Replacement of L(34) of tRNA(2Ile) molecule enzymatically with unmodified C(34) resulted in a marked reduction of the isoleucine-accepting activity and, surprisingly, in the appearance of methionine-accepting activity. Thus, both the codon and amino-acid specificity of this tRNA are converted by a single post-transcriptional modification of the first position of the anticodon during tRNA maturation.


Asunto(s)
Codón , Escherichia coli/genética , Procesamiento Postranscripcional del ARN , ARN Mensajero , ARN de Transferencia Aminoácido-Específico/genética , Anticodón , Secuencia de Bases , Datos de Secuencia Molecular , ARN de Transferencia de Isoleucina/genética
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