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1.
Medicina (Kaunas) ; 60(4)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38674188

RESUMEN

Background and Objectives: This study explored the efficacy of customized anti-gravity treadmill (AGT) training, with adjustments in speed and incline, on rehabilitation outcomes for stroke patients, focusing on knee extensor muscle strength, joint angle, balance ability, and activities of daily living (ADLs). Materials and Methods: In this study, 30 individuals diagnosed with a stroke were divided into three groups. Experimental group 1 (EG1) underwent training without changes to speed and incline, experimental group 2 (EG2) received training with an increased incline, and experimental group 3 (EG3) underwent training with increased speed. Initially, all participants received AGT training under uniform conditions for two weeks. Subsequently, from the third to the sixth week, each group underwent their specified training intervention. Evaluations were conducted before the intervention and six weeks post-intervention using a manual muscle strength tester for knee strength, TETRAX for balance ability, Dartfish software for analyzing knee angle, and the Korean version of the Modified Barthel Index (K-MBI) for assessing activities of daily living. Results: Within-group comparisons revealed that AGT training led to enhancements in muscle strength, balance ability, joint angle, and ADLs across all participant groups. Between-group analyses indicated that EG2, which underwent increased incline training, demonstrated significant improvements in muscle strength and balance ability over EG1. EG3 not only showed significant enhancements in muscle strength, joint angle, and ADLs when compared to EG1 but also surpassed EG2 in terms of knee strength improvement. Conclusions: In conclusion, the application of customized AGT training positively impacts the rehabilitation of stroke patients, underscoring the importance of selecting a treatment method tailored to the specific needs of each patient.


Asunto(s)
Actividades Cotidianas , Terapia por Ejercicio , Rehabilitación de Accidente Cerebrovascular , Humanos , Rehabilitación de Accidente Cerebrovascular/métodos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Terapia por Ejercicio/métodos , Resultado del Tratamiento , Fuerza Muscular/fisiología , Equilibrio Postural/fisiología , Sobrevivientes/estadística & datos numéricos , Accidente Cerebrovascular/fisiopatología , Prueba de Esfuerzo/métodos
2.
Medicina (Kaunas) ; 59(5)2023 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-37241089

RESUMEN

Stroke remains a leading cause of disability worldwide, with survivors often experiencing impairments in balance, pain, spasticity, and control that limit their ability to perform daily living activities. Extracorporeal shock wave therapy (ESWT) has emerged as a potential treatment modality to improve these outcomes in stroke patients. This review aims to provide a comprehensive examination of the effects of ESWT on stroke patients, focusing on the theoretical background, balance, pain reduction, muscle spasticity and control, and upper and lower extremities. This study reviewed the use of ESWT in treating balance, pain, and spasticity in stroke patients, focusing on articles published in PubMed between January 2003 and January 2023. Systematic reviews related to stroke were used to provide an overview of stroke, and a total of 33 articles related to balance, pain, and spasticity were selected. ESWT has several shock wave generation methods and application methods, and it has been shown to have positive therapeutic effects on various aspects of rehabilitation for stroke patients, such as improving balance, reducing pain, decreasing muscle spasticity and increasing control, and enhancing functional activities of the upper and lower extremities. The efficacy of ESWT may vary depending on the patient's condition, application method, and treatment area. Therefore, it is important to apply ESWT according to the individual characteristics of each patient in clinical practice to maximize its potential benefits.


Asunto(s)
Tratamiento con Ondas de Choque Extracorpóreas , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Humanos , Espasticidad Muscular/etiología , Espasticidad Muscular/terapia , Tratamiento con Ondas de Choque Extracorpóreas/efectos adversos , Tratamiento con Ondas de Choque Extracorpóreas/métodos , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Rehabilitación de Accidente Cerebrovascular/métodos , Actividades Cotidianas , Resultado del Tratamiento
3.
PLoS Genet ; 12(2): e1005829, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26828946

RESUMEN

Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of peripheral neuropathies with diverse genetic causes. In this study, we identified p.I43N mutation in PMP2 from a family exhibiting autosomal dominant demyelinating CMT neuropathy by whole exome sequencing and characterized the clinical features. The age at onset was the first to second decades and muscle atrophy started in the distal portion of the leg. Predominant fatty replacement in the anterior and lateral compartment was similar to that in CMT1A caused by PMP22 duplication. Sural nerve biopsy showed onion bulbs and degenerating fibers with various myelin abnormalities. The relevance of PMP2 mutation as a genetic cause of dominant CMT1 was assessed using transgenic mouse models. Transgenic mice expressing wild type or mutant (p.I43N) PMP2 exhibited abnormal motor function. Electrophysiological data revealed that both mice had reduced motor nerve conduction velocities (MNCV). Electron microscopy revealed that demyelinating fibers and internodal lengths were shortened in both transgenic mice. These data imply that overexpression of wild type as well as mutant PMP2 also causes the CMT1 phenotype, which has been documented in the PMP22. This report might expand the genetic and clinical features of CMT and a further mechanism study will enhance our understanding of PMP2-associated peripheral neuropathy.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth/genética , Enfermedades Desmielinizantes/genética , Genes Dominantes , Proteína P2 de Mielina/genética , Secuencia de Aminoácidos , Animales , Enfermedad de Charcot-Marie-Tooth/patología , Enfermedad de Charcot-Marie-Tooth/fisiopatología , Segregación Cromosómica , Simulación por Computador , Fenómenos Electrofisiológicos , Familia , Femenino , Células HEK293 , Humanos , Pierna/fisiopatología , Imagen por Resonancia Magnética , Masculino , Ratones Transgénicos , Datos de Secuencia Molecular , Mutación , Proteína P2 de Mielina/química , Linaje , Fenotipo , Nervio Sural/patología , Nervio Sural/fisiopatología
4.
Ann Neurol ; 79(2): 231-43, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26506222

RESUMEN

OBJECTIVE: Distal myopathy is a heterogeneous group of muscle diseases characterized by predominant distal muscle weakness. A study was done to identify the underlying cause of autosomal recessive adolescent onset distal myopathy. METHODS: Four patients from 2 unrelated Korean families were evaluated. To isolate the genetic cause, exome sequencing was performed. In vitro and in vivo assays using myoblast cells and zebrafish models were performed to examine the ADSSL1 mutation causing myopathy pathogenesis. RESULTS: Patients had an adolescent onset distal myopathy phenotype that included distal dominant weakness, facial muscle weakness, rimmed vacuoles, and mild elevation of serum creatine kinase. Exome sequencing identified completely cosegregating compound heterozygous mutations (p.D304N and p.I350fs) in ADSSL1, which encodes a muscle-specific adenylosuccinate synthase in both families. None of the controls had both mutations, and the mutation sites were located in well-conserved regions. Both the D304N and I350fs mutations in ADSSL1 led to decreased enzymatic activity. The knockdown of the Adssl1 gene significantly inhibited the proliferation of mouse myoblast cells, and the addition of human wild-type ADSSL1 reversed the reduced viability. In an adssl1 knockdown zebrafish model, muscle fibers were severely disrupted, which was evaluated by myosin expression and birefringence. In these conditions, supplementing wild-type ADSSL1 protein reversed the muscle defect. INTERPRETATION: We suggest that mutations in ADSSL1 are the novel genetic cause of the autosomal recessive adolescent onset distal myopathy. This study broadens the genetic and clinical spectrum of distal myopathy and will be useful for exact molecular diagnostics.


Asunto(s)
Adenilosuccinato Sintasa/genética , Miopatías Distales/genética , Adulto , Edad de Inicio , Animales , Animales Modificados Genéticamente , Modelos Animales de Enfermedad , Miopatías Distales/enzimología , Miopatías Distales/fisiopatología , Femenino , Humanos , Masculino , Ratones , Mutación , Linaje , Fenotipo , República de Corea , Adulto Joven , Pez Cebra , Proteínas de Pez Cebra
5.
J Phys Ther Sci ; 29(7): 1205-1207, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28744048

RESUMEN

[Purpose] The purpose of this study is to investigate effects of kinesio taping to the quadriceps femoris on functions of elderly women. [Subjects and Methods] The subjects of this study were 22 elderly women with osteoarthritis, who were divided into two groups of a general exercise group 12 elderly and a kinesiology taping group 12 elderly. Two groups underwent a 30-min exercise for strengthening the lower limb muscles three times per week for four weeks. After the exercise, the kinesiology taping group was treated by the kinesio taping. Kinesio tapes were attached to the quadriceps femoris, three times per week for four weeks. The Korean Western Ontario and McMaster Universities Osteoarthritis Index, sit to standing, and Time up & Go test were used for assessment before and after the intervention. [Results] As a result, the kinesiology taping group showed significant differences in the Korean Western Ontario and McMaster Universities Osteoarthritis Index, sit to standing, and Time up & Go test between pre- and post-intervention, while the general exercise group showed no significant differences in pre- and post-intervention. There was a significant difference in between-group comparison. [Conclusion] The kinesio taping for the quadriceps femoris was effective on improving functions of elderly women with osteoarthritis.

6.
J Phys Ther Sci ; 28(9): 2426-2429, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27799662

RESUMEN

[Purpose] This study aimed to examine the effect of upper extremity training in the standing position on trunk alignment of patients with stroke. [Subjects and Methods] Twelve stroke patients were enrolled in the study and divided into two groups: a group of six patients in a sitting position and a group of six patients in a standing position. Upper extremity training for 30 min per day, five times a week for six weeks was given to subjects in both groups. In order to assess trunk alignment, lumbar lordosis and thoracic kyphosis were examined before and after upper extremity training using Formetric 4D. [Results] After training the standing position group had no significant change in lumbar lordosis but a significant change in thoracic kyphosis. The sitting position group showed no significant changes in either lumbar lordosis or thoracic kyphosis. The comparison between groups showed there was no significant difference in the change in lumbar lordosis but there was a significant difference in the change in thoracic kyphosis. [Conclusion] Examination of trunk alignment showed that upper extremity training conducted in a standing position reduced thoracic kyphosis more than in a sitting position.

7.
J Phys Ther Sci ; 28(6): 1686-90, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27390395

RESUMEN

[Purpose] The aim of this study was to identify the contributions of balance to gait and motor function in chronic stroke. [Subjects and Methods] Twenty-three outpatients participated in a cross-sectional assessment. Gait ability was assessed using the functional ambulation category, self-paced 10-m walking speed, and fastest 10-m walking speed. Standing balance and trunk control measures included the Berg Balance Scale and the Trunk Impairment Scale. Univariate and multivariate regression analyses were performed. [Results] Balance was the best predictor of the FAC, self-paced walking speed, and fastest walking speed, accounting for 57% to 61% of the variances. Additionally, the total score of TIS was the only predictor of the motor function of the lower limbs and the dynamic balance of TIS was a predictor of the motor function of the upper limbs, accounting for 41% and 29% of the variance, respectively. [Conclusion] This study demonstrated the relative contribution of standing balance and trunk balance to gait ability and motor function. They show that balance has a high power of explanation of gait ability and that trunk balance is a determinant of motor function rather than gait ability.

8.
Brain Sci ; 13(5)2023 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-37239271

RESUMEN

Functional movements of the human body occur multifacetedly. This pilot study investigated the effects of neurorehabilitation training, including diagonal movements, balance, gait, fall efficacy, and activities of daily living in stroke patients. Twenty-eight patients diagnosed with stroke by a specialist were divided into experimental groups applying diagonal exercise training and control groups applying sagittal exercise training. The five times sit-to-stand test (FTSST), timed up and go (TUG) test, and Berg balance scale (BBS) were used to evaluate balance ability, the falls efficacy scale (FES) was used to evaluate fall efficacy, and the modified Barthel index (MBI) was used to evaluate activities of daily living. All evaluations were conducted once prior to intervention implementation and again six weeks after the final intervention. In the study results, the experimental group to which the diagonal exercise training was applied had statistically significant changes in FTSST, BBS, and FES compared to the control group. In conclusion, the rehabilitation program, including diagonal exercise training, increased the patient's balance and reduced the fear of falling.

9.
Brain Sci ; 13(4)2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37190652

RESUMEN

BACKGROUND: This study was conducted to investigate the effects of extracorporeal shock wave therapy on the improvement of walking ability through a reduction in spasticity in stroke patients. METHODS: Thirty-three patients diagnosed with ischemic stroke by a rehabilitation medicine specialist were randomly assigned to three groups. The patients were divided into experimental group 1 in which shock waves were applied to the muscle-tendon junction, experimental group 2 in which shock waves were applied to the middle of the muscle, and experimental group 3 in which shock waves were applied to both the muscle-tendon junction and the middle of the muscle. The MAS was used to evaluate spasticity in the subjects, and the Dartfish software was used to measure knee and ankle angles during heel-off when walking. RESULTS: Based on the results of the study, a significant decrease in spasticity and increased joint angles were found in experimental groups 1 and 3 compared to experimental group 2, and the change in joint angle was significantly greater in experimental group 3 than in experimental groups 1 and 2. CONCLUSIONS: These results indicate that treatment effect may vary depending on the application site of the shock wave, and to obtain the best treatment effect, the shock wave should be applied to both the muscle-tendon junction and the middle part of the muscle.

10.
Mol Microbiol ; 69(3): 621-32, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18573169

RESUMEN

The concerted interconnection between processes driving DNA synthesis, division septum formation and cell wall synthesis and remodelling in rapidly growing bacteria requires precise co-ordination by signalling mechanisms that are, for the most part, unknown. The YycG (sensor histidine kinase)-YycF (response regulator/transcription factor) two-component system of Bacillus subtilis controls the synthesis of enzymes and their inhibitors that function in cell wall remodelling and cell separation. Here it is shown that the YycG sensor histidine kinase is a component of the division septum in growing cells. RT-PCR quantification of YycF approximately PO(4)-regulated gene transcription, in wild type and FtsZ-depleted, septum-less cells, indicated that YycG kinase activity on YycF is dependent on YycG localization to a division septum. The data support a model in which the YycG sensor kinase perceives information at the division septum and regulates the reciprocal synthesis of autolysins and autolysin inhibitors to co-ordinate growth and division with cell wall restructuring.


Asunto(s)
Bacillus subtilis/enzimología , Proteínas Bacterianas/metabolismo , División Celular , Pared Celular/enzimología , Proteínas Quinasas/metabolismo , Bacillus subtilis/química , Bacillus subtilis/genética , Bacillus subtilis/fisiología , Proteínas Bacterianas/análisis , Proteínas Bacterianas/genética , Nucléolo Celular/enzimología , Pared Celular/genética , Pared Celular/fisiología , Histidina Quinasa , Proteínas Quinasas/análisis , Proteínas Quinasas/genética , Transducción de Señal
11.
Mol Med Rep ; 14(4): 3362-8, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27573046

RESUMEN

Mutations in the Dynactin 1 (DCTN1) gene have been demonstrated to result in various neurodegenerative diseases, including distal hereditary motor neuropathy type 7B (dHMN7B), Perry syndrome, amyotrophic lateral sclerosis and amyotrophic lateral sclerosis­frontotemporal dementia. However, since the first dHMN7B patient with a DCTN1 mutation was described in 2003, to the best of our knowledge no further cases have been reported. In the present study, the DCTN1 p.G59S mutation was identified in two unrelated families from a total of 24 Korean families with dHMN, by whole exome sequencing. Codon 59 appears to be the mutational hot spot in the DCTN1 gene, as all described dHMN7B patients to date have harbored an identical p.G59S mutation. The families of the present study with the DCTN1 mutation had a milder disease with a later onset compared with the previously described patients. No affected family members exhibited facial muscle weakness or bulbar involvement. One family member demonstrated vocal cord palsy as the initial sign of disease; however, in the other family hand muscle weakness was the first major symptom. No affected patients demonstrated sensory loss or upper motor neuron involvements. Although this is only the second report of dHMN7B resulting from a DCTN1 mutation, the frequency of the DCTN1 mutation was not low in the Korean population examined, and clinical heterogeneities were observed in patients with the DCTN1 mutation. Therefore, it may be beneficial to screen all dHMN patients for the DCTN1 mutation.


Asunto(s)
Complejo Dinactina/genética , Atrofia Muscular Espinal/genética , Mutación Puntual , Adulto , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad
12.
Korean J Women Health Nurs ; 20(1): 72-82, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37684782

RESUMEN

PURPOSE: This study was conducted to investigate sexual behaviors and influencing factors affecting premenopausal women who have breast cancer and have undergone surgery. METHODS: Seventy premenopausal women, ranging between 35~55 years of age, were included in this study. Sexual behaviors were evaluated using the WSBQ-F (Wilmoth Sexual Behaviors Questionnaire-Female). The in-depth interview was analyzed utilizing content analysis. RESULTS: There were no significant differences regarding the type of surgery, age, time of marriage, education level, occupation, chemotherapy, use of Tamoxifen, and radiotherapy in the sexual activities of premenopausal women with breast cancer. However, quality-related information utilizing qualitative in-depth interviews, revealed 3 issues regarding sexual behaviors.. Participants reported physical discomfort such as vaginal dryness, dyspareunia, emotional changes such as decrease in sexual confidence, and interaction-related changes such as mandatory sexual life, sexual intimacy with one's partner, and being more active sexual behaviors. CONCLUSION: There were complex changes associated with sexual behavior after surgery for women with breast cancer which included various events related to stress regarding sexual behavior. Communication between women with breast cancer, their partners, and medical caregivers has a ability to maximize the sense of sexual wellbeing while minimizing the sexual crises.

13.
J Mov Disord ; 7(1): 13-8, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24926405

RESUMEN

OBJECTIVE: Cognitive impairment is a common nonmotor symptom of Parkinson's disease (PD) and is associated with high mortality, caregiver distress, and nursing home placement. The risk factors for cognitive decline in PD patients include advanced age, longer disease duration, rapid eye movement sleep behavior disorder, hallucinations, excessive daytime sleepiness, and nontremor symptoms including bradykinesia, rigidity, postural instability, and gait disturbance. We conducted a cross-sectional study to determine which types of sleep disturbances are related to cognitive function in PD patients. METHODS: A total of 71 PD patients (29 males, mean age 66.46 ± 8.87 years) were recruited. All patients underwent the Mini- Mental State Examination (MMSE) and the Korean Version of the Montreal Cognitive Assessments (MoCA-K) to assess global cognitive function. Sleep disorders were evaluated with the Stanford Sleepiness Scale, Epworth Sleepiness Scale, Insomnia Severity Index (ISI), Pittsburg Sleep Quality Index, and Parkinson's Disease Sleep Scale in Korea (PDSS). RESULTS: The ISI was correlated with the MMSE, and total PDSS scores were correlated with the MMSE and the MoCA-K. In each item of the PDSS, nocturnal restlessness, vivid dreams, hallucinations, and nocturnal motor symptoms were positively correlated with the MMSE, and nocturnal restlessness and vivid dreams were significantly related to the MoCA-K. Vivid dreams and nocturnal restlessness are considered the most powerful correlation factors with global cognitive function, because they commonly had significant correlation to cognition assessed with both the MMSE and the MoCA-K. CONCLUSIONS: We found a correlation between global cognitive function and sleep disturbances, including vivid dreams and nocturnal restlessness, in PD patients.

14.
J Korean Assoc Oral Maxillofac Surg ; 39(4): 168-74, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24471038

RESUMEN

OBJECTIVES: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. MATERIALS AND METHODS: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. RESULTS: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). CONCLUSION: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

15.
J Bacteriol ; 187(15): 5419-26, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16030236

RESUMEN

Of the numerous two-component signal transduction systems found in bacteria, only a very few have proven to be essential for cell viability. Among these is the YycF (response regulator)-YycG (histidine kinase) system, which is highly conserved in and specific to the low-G+C content gram-positive bacteria. Given the pathogenic nature of several members of this class of bacteria, the YycF-YycG system has been suggested as a prime antimicrobial target. In an attempt to identify genes involved in regulation of this two-component system, a transposon mutagenesis study was designed to identify suppressors of a temperature-sensitive YycF mutant in Bacillus subtilis. Suppressors could be identified, and the prime target was the yycH gene located adjacent to yycG and within the same operon. A lacZ reporter assay revealed that YycF-regulated gene expression was elevated in a yycH strain, whereas disruption of any of the three downstream genes within the operon, yycI, yycJ, and yycK, showed no such effect. The concentrations of both YycG and YycF, assayed immunologically, remained unchanged between the wild-type and the yycH strain as determined by immunoassay. Alkaline phosphatase fusion studies showed that YycH is located external to the cell membrane, suggesting that it acts in the regulation of the sensor domain of the YycG sensor histidine kinase. The yycH strain showed a characteristic cell wall defect consistent with the previously suggested notion that the YycF-YycG system is involved in regulating cell wall homeostasis and indicating that either up- or down-regulation of YycF activity affects this homeostatic mechanism.


Asunto(s)
Bacillus subtilis/fisiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos/genética , Proteínas Quinasas/metabolismo , Transducción de Señal , Transactivadores/genética , Bacillus subtilis/genética , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/farmacología , Pared Celular/metabolismo , Pared Celular/fisiología , Genes Reguladores , Histidina Quinasa , Homeostasis , Operón , Proteínas Quinasas/genética , Temperatura , Transactivadores/metabolismo , Transactivadores/farmacología
16.
J Bacteriol ; 185(23): 6756-63, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14617639

RESUMEN

Paraquat (methyl viologen)-resistant mutants of Streptomyces coelicolor A3(2) that grew and sporulated normally in the presence of paraquat were isolated. Based on the positions of the mutant loci in the genetic map, we isolated the pqr (paraquat resistance) gene whose mutation (pqr501) caused a dominant paraquat-resistant phenotype. The pqr locus consists of two genes (pqrA and pqrB) that form a transcription unit. The pqrA gene encodes a protein with a TetR-like DNA-binding motif, and the pqrB gene encodes a putative efflux pump of the major facilitator superfamily. The pqr501 mutation was a base substitution changing arginine-18 to glutamine (R18Q) near the helix-turn-helix motif in PqrA. A pqrA null mutant exhibited similar paraquat resistance, and an increase in the amount of pqrA promoter-driven transcripts of about eightfold was observed for the pqrA501 mutant. These results suggest that PqrA is a negative regulator of its own operon. Deletion of the pqrAB operon caused cells to be very sensitive to paraquat, consistent with the prediction that PqrB may function as a paraquat-efflux pump. Purified PqrA protein specifically bound to the pqrA promoter region, whereas mutant R18Q protein did not, indicating that PqrA is a direct autoregulator of its own operon.


Asunto(s)
Genes Bacterianos , Herbicidas/farmacología , Operón , Paraquat/farmacología , Streptomyces/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Farmacorresistencia Bacteriana/genética , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Datos de Secuencia Molecular , Mutación , Regiones Promotoras Genéticas , Unión Proteica , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Alineación de Secuencia , Streptomyces/efectos de los fármacos
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