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1.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(9): 1251-1256, 2022 Sep 06.
Artigo em Zh | MEDLINE | ID: mdl-36207888

RESUMO

Objective: To determine the characteristics and progress of the visual acuity and refractive state of schoolchildren in Huangzhong District, Xining City, Qinghai Province in China. Methods: Cohort study. Department of Ophthalmology, Beijing Children's Hospital carried out a cohort study by collecting the visual acuity and refractive state of Grade 1-5 schoolchildren among 16 primary schools in Huangzhong District, Xining City, Qinghai Province in September 2020 and July 2021. Cycloplegic retinoscopy with eye drop which contained tropicamide (0.5%) and phenylephrine hydrochloride (0.5%) was performed in children with low vision(<1.0). Myopia was defined as the spherical equivalent (SE) ≤-0.5 D after cycloplegic retinoscopy. Measurement data was analyzed by t-test and enumeration data was analyzed by χ2 test. Multiple linear regression was used to analyze the influencing factors. Results: The 2 489 individuals with repeated tests in two years were included in the follow-up study, among whom the prevalence of myopia was 26.24%(653/2 489) in 2020, while 32.94% (820/2 489)respectively in 2021. The incidence of myopia in one school year from grades 1 to 5 was 11.19%(47/420), 5.44%(21/386), 6.39%(25/391), 11.52%(44/382) and 11.67%(30/257). The average SE of children in all grades in 2021 increased negatively from the previous year (Grade 1 to Grade 5 increased respectively: 0.40 D, 0.69 D, 0.62 D, 0.52 D and 0.37 D). Conclusions: The prevalence of myopia among schoolchildren in Huangzhong District, Xining City, Qinghai Province was relatively high. There were two peaks of myopia incidence in the first, fourth and fifth grades. Female, age, and the baseline of SE were the related influencing factors for myopia progression.


Assuntos
Midriáticos , Miopia , Criança , Estudos de Coortes , Feminino , Seguimentos , Humanos , Miopia/epidemiologia , Soluções Oftálmicas , Fenilefrina , Prevalência , Estudos Prospectivos , Tropicamida
2.
Eur Rev Med Pharmacol Sci ; 23(13): 5621-5627, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31298314

RESUMO

OBJECTIVE: Many studies have demonstrated that the abnormal microRNAs (miRNAs) expression plays crucial roles in the development of human cancers including cervical cancer (CC). However, the expression and the underlying mechanism of miR-299-3p in CC remain unclear. MATERIALS AND METHODS: In this study, the quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect miR-299-3p expression level in CC cell lines. The cell proliferation assay, colony formation assay, and transwell invasion assay were conducted to investigate the biological functions of miR-299-3p. Followingly, the Luciferase activity reporter and the Western blot assays were conducted to validate the transcription factor 4 (TCF4) as a direct target of miR-299-3p. RESULTS: MiR-299-3p expression level was reduced in CC cell lines compared with the normal cell line. The overexpression of miR-299-3p inhibits CC cell growth and invasion. Furthermore, TCF4 was validated as a direct target of miR-299-3p. In addition, TCF4 overexpression reversed the inhibitory effects of miR-299-3p on CC cell behaviors. CONCLUSIONS: Taken together, our results illustrated that miR-299-3p acts as a tumor suppressor to inhibit CC cell behaviors by targeting TCF4.


Assuntos
Proliferação de Células , MicroRNAs/metabolismo , Fator de Transcrição 4/metabolismo , Regiões 3' não Traduzidas , Antagomirs/metabolismo , Sequência de Bases , Linhagem Celular Tumoral , Movimento Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Alinhamento de Sequência , Fator de Transcrição 4/química , Fator de Transcrição 4/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
3.
Artigo em Zh | MEDLINE | ID: mdl-31550757

RESUMO

Objective: Using propensity score matching method (PSM) to investigate the clinical effect of postoperative adjuvant radiotherapy and postoperative concurrent chemoradiotherapy for locally advanced hypopharyngeal squamous cell carcinoma. Methods: From July 2007 to July 2018,174 postoperative patients with locally advanced hypopharyngeal squamous cell carcinoma were enrolled in pre-PSM cohort, including 168 males and 6 females, the median age was 60 years old (ranged from 37 to 79 years old).Loco-regional control (LRC),progression-free survival (PFS) and overall survival (OS) were compared and analyzed between the patients treated with postoperative adjuvant radiotherapy and postoperative concurrent chemoradiotherapy (cisplatin was given in a dose of 80 mg/m(2) on days 1, 22, and 43). After the propensity score matching (PSM), 61 sub-pairs of 122 patients were generated in post-PSM cohort. Survival rate were assessed with Kaplan-Meier method and Log-rank test. Results: After the propensity score matching(PSM), 61 sub-pairs of 122 patients were generated in post-PSM cohort.The patients were followed up for 3-135 months, the median follow-up was 42 months. No significant differences in 3-year and 5-year LRC, PFS, OS were observed between the two groups (P>0.05) . For postoperative patients who had high-risk factors (extracapsular extension of nodal disease, and/or vascular embolism, and/or lymph node metastasis≥2, and/or positive surgical margin, and/or perineural infiltration),there were significant differences between the two groups in 3-year PFS (60.99% vs 84.49%,P<0.05), 5-year PFS (35.47% vs 56.97%,P<0.05) and 5-year LRC (41.02% vs 68.50%, P<0.05), but no significant difference was found in OS between the two groups (P>0.05). Conclusion: Postoperative concurrent chemoradiotherapy was more efficacious than postoperative radiotherapy alone in terms of loco-regional control and PFS for high-risk postoperative patients with locally advanced hypopharyngeal squamous cell carcinoma.


Assuntos
Carcinoma de Células Escamosas , Quimiorradioterapia , Neoplasias Hipofaríngeas , Radioterapia Adjuvante , Adulto , Idoso , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Estudos de Coortes , Feminino , Humanos , Neoplasias Hipofaríngeas/tratamento farmacológico , Neoplasias Hipofaríngeas/radioterapia , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida
4.
Scand J Immunol ; 67(5): 441-7, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18312485

RESUMO

The NKG2D is an activating immunoreceptor expressed by NK cells and CD8(+) T cells. Engagement of NKG2D by its ligands is critical for both innate and adoptive immunity. While the overexpression of NKG2D ligands on certain tumour cells has previously been demonstrated, little is known about NKG2D ligand expression on human laryngeal tumour cells. In this study, we first verified that the interaction between NKG2D and its ligands was critical for NK cell-based immune response to human laryngeal squamous carcinoma cells Hep-2. This NKG2D-mediated effect was observed by transfecting the recombinant eukaryotic expression vector pEGFP-N1/NKG2D as well as the NKG2D blockade. The mRNA and protein expression of NKG2D ligands, MHC class I-related chain molecules A (MICA) and UL16-binding proteins (ULBPs), in human laryngeal carcinoma cell line Hep-2 and fresh tumour tissues were evaluated. Compared with non-tumour tissues of vocal cords polyps, MICA and ULBP-3 were strongly overexpressed on both the human laryngeal carcinoma cell line Hep-2 and fresh human laryngeal carcinoma tissues. The mechanism and impact of NKG2D ligands overexpression on NK cell-mediated anti-laryngeal cancer immune response would require further investigation.


Assuntos
Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Laríngeas/imunologia , Neoplasias Laríngeas/metabolismo , Adulto , Idoso , Western Blotting , Carcinoma de Células Escamosas/patologia , Linhagem Celular , Citotoxicidade Imunológica , Feminino , Citometria de Fluxo , Proteínas Ligadas por GPI , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Células Matadoras Naturais/imunologia , Neoplasias Laríngeas/patologia , Ligantes , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Artigo em Zh | MEDLINE | ID: mdl-29764016

RESUMO

Objective: To compare the treatment outcomes for locally advanced hypopharyngeal carcinoma between surgery plus radio(chemo) therapy(SRT) and non-surgery chemoradiotherapy(CRT). Methods: A total of 119 patients diagnosed with advanced hypopharyngeal carcinoma without distant metastases between 2010 and 2014 were identified in the Chinese People's Liberation Army General Hospital, and they were divided into 2 groups: 42 cases in SRT group and 77 cases in CRT group. Patients' clinical information was collected. Survival rates and prognostic factors were analyzed by the Kaplan-Meier method with SPSS 23.0 software. The survival rates, laryngeal preservation rates and complication rates were compared between the two groups using the chi-square test.Among the 119 patients, 112 were males and 7 were females. Age ranged from 27 to 78 years, with an average age of 57 years. Results: There were no significant difference between the SRT and CRT group for five-year disease-free survival (DFS, 53.9% vs. 45.1%, χ(2)=1.251, P=0.263) and overall survival (OS, 54.9% vs. 45.6%, χ(2)=1.749, P=0.186). Compared to SRT group, CRT group did not showed the significant increase of treatment complications (χ(2)=0.858, P=0.354), with a higher laryngeal preservation rate (50.0% vs. 71.4%, χ(2)=6.493, P=0.011). Conclusions: Advanced hypopharyngeal carcinoma is of high malignancy and poor prognosis. Combined modality treatment is a main approach for advanced hypopharyngeal cancer. SRT offers disease-free survival and overall survival rates equivalent to CRT, but with a higher laryngeal preservation rate.


Assuntos
Carcinoma de Células Escamosas/terapia , Neoplasias Hipofaríngeas/terapia , Adulto , Idoso , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Quimiorradioterapia , Terapia Combinada/métodos , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Hipofaríngeas/mortalidade , Neoplasias Hipofaríngeas/patologia , Hipofaringe , Estimativa de Kaplan-Meier , Laringe , Masculino , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
6.
Eur Rev Med Pharmacol Sci ; 21(21): 4810-4818, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29164582

RESUMO

OBJECTIVE: Endometrial cancer is one of the three most common types of gynecologic cancer. The global incidence has increased in recent years. microRNAs (miRNAs) regulate numerous biological processes by binding to the 3'UTR of target mRNA to down-regulate protein synthesis. PATIENTS AND METHODS: Endometrial cancer patients received surgeries in our hospital were enrolled. MiR-15a-5p mimic or miR-15a-5p inhibitor was transfected into HEC-1-A cells by lentivirus. Colony formation assay was applied for detecting cell proliferation. Real-time PCR was performed to test miRNA and mRNA expression. Western blot was used to detect protein level. ChIP was adopted to test transcription activation. TOP/FOP was tested to determine Wnt signaling pathway activity. A dual-luciferase reporter assay was used to confirm miRNA target. RESULTS: miR-15a-5p was decreased in endometrial cancer cells and tissues. miR-15a-5p overexpression restrained HEC-1-A cell proliferation and stemness. miR-15a-5p mimic transfection reduced mRNA and protein levels of the proteins which are related to cell proliferation and Wnt signaling pathway. MiR-15a-5p targeted a putative binding site in the 3'-UTR of Wnt3a gene, thus regulating Wnt signaling pathway. miR-15a-5p overexpression decreased Wnt3a protein expression. Wnt3a presented significant negative correlation with the miR-15a-5p level in endometrial cancer patients. CONCLUSIONS: miR-15a-5p is a regulator of endometrial cancer cell proliferation by directly targeting Wnt3a to block Wnt signaling pathway.


Assuntos
MicroRNAs/metabolismo , Proteína Wnt3A/metabolismo , Regiões 3' não Traduzidas , Antagomirs/metabolismo , Sequência de Bases , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Feminino , Humanos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Alinhamento de Sequência , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt , Proteína Wnt3A/antagonistas & inibidores , Proteína Wnt3A/genética
7.
Eur Rev Med Pharmacol Sci ; 21(21): 4819-4827, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29164581

RESUMO

OBJECTIVE: To dissect the functioning mode of miR-30c on giant cell tumor of bone cell metastasis and growth and provide therapeutic targets for giant cell tumor of bone. PATIENTS AND METHODS: By quantitative Real-time polymerase chain reaction (qRT-PCR), miR-30c expression level in 62 pairs of giant cell tumor of bone cells tissue samples and five breast cancer-derived cell lines. Using miR-30c mimics and inhibitors, we analyzed the effects of miR-30c over-expression and knockdown on cell proliferation, invasion, and migration. Dual-luciferase activity assay was recruited to examine the potential target gene HOXA1, which predicted by several databases. Protein level was studied using Western blot. RESULTS: MiR-30c expressed significantly lower in giant cell tumor of bone tissue samples and cell lines. Over-expression miR-30c in giant cell tumor of bone cells decreased the cell proliferation, invasion, and migration abilities while down-regulation miR-30c in giant cell tumor of bone cells increased these abilities oppositely. Dual-luciferase and Western blot confirmed HOXA1 as a target gene of miR-30c. Furthermore, up-regulation of HOXA1 reserved the suppressive effect of miR-30c over-expression on cell growth and progression. CONCLUSIONS: miR-30c could suppress giant cell tumor of bone cell proliferation and progression via HOXA1, which might provide a new target for giant cell tumor of bone diagnosis and therapy.


Assuntos
Neoplasias Ósseas/genética , Movimento Celular/genética , Tumor de Células Gigantes do Osso/genética , Tumor de Células Gigantes do Osso/patologia , Proteínas de Homeodomínio/genética , MicroRNAs/genética , Metástase Neoplásica/genética , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação para Baixo , Técnicas de Silenciamento de Genes , Tumor de Células Gigantes do Osso/metabolismo , Humanos , Metástase Neoplásica/patologia , Regulação para Cima
8.
Sci Rep ; 6: 33825, 2016 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-27650797

RESUMO

Approximately 20% of HER2 positive breast cancer develops disease recurrence after adjuvant trastuzumab treatment. This study aimed to develop a molecular prognostic model that can reliably stratify patients by risk of developing disease recurrence. Using miRNA microarrays, nine miRNAs that differentially expressed between the recurrent and non-recurrent patients were identified. Then, we validated the expression of these miRNAs using qRT-PCR in training set (n = 101), and generated a 2-miRNA (miR-4734 and miR-150-5p) based prognostic signature. The prognostic accuracy of this classifier was further confirmed in an internal testing set (n = 57), and an external independent testing set (n = 53). Besides, by comparing the ROC curves, we found the incorporation of this miRNA based classifier into TNM stage could improve the prognostic performance of TNM system. The results indicated the 2-miRNA based signature was a reliable prognostic biomarker for patients with HER2 positive breast cancer.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Perfilação da Expressão Gênica , MicroRNAs/genética , Recidiva Local de Neoplasia/patologia , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapêutico , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Estimativa de Kaplan-Meier , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Modelos de Riscos Proporcionais , Curva ROC , Reprodutibilidade dos Testes , Fatores de Tempo , Trastuzumab/farmacologia
9.
FEBS Lett ; 276(1-2): 175-80, 1990 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-2125006

RESUMO

A fusion protein, denoted PsaC1, which contains an amino-terminal extension of five amino acids (MEHSM...) and is derived from an in vitro modified form of the psaC gene of Synechococcus sp. PCC 7002, has been over-expressed in Escherichia coli. The product of the psaD gene of Nostoc sp. PCC 8009 has similarly been over-expressed. The PsaC1 and PsaD proteins can be combined with the photosystem I core protein of Synechococcus sp. PCC 6301 to reconstitute electron transport from P700 to the terminal FA/FB acceptors. Reconstitution was found to be absolutely dependent on reinsertion of the iron-sulfur clusters in the PsaC1 apoprotein and on the presence of the PsaD protein. This implies that the PsaC1 holoprotein does not bind solely to the PsaA/PsaB heterodimer but rather that its interaction with these proteins is mediated through the PsaD protein.


Assuntos
Cianobactérias/genética , Escherichia coli/genética , Proteínas de Membrana , Peptídeos/genética , Complexo de Proteínas do Centro de Reação Fotossintética/genética , Complexo de Proteína do Fotossistema I , Proteínas/genética , Sequência de Aminoácidos , Sequência de Bases , Cianobactérias/metabolismo , Transporte de Elétrons , Cinética , Dados de Sequência Molecular , Peso Molecular , Peptídeos/metabolismo , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Plasmídeos , Proteínas/isolamento & purificação , Proteínas/metabolismo , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Mapeamento por Restrição
12.
Arch Biochem Biophys ; 264(2): 657-64, 1988 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-3135783

RESUMO

Incubation of Synechocystis PCC 6714 in liquid medium devoid of Na+ results in a light-dependent loss in photosynthetic O2 evolving capacity within 1 h. Photosynthetic activity is fully restored and normal growth resumes after Na+ is supplied to culture medium of depleted cells. If external Na+ is provided as soon as inhibition becomes complete, normal photosynthesis is restored within 3 min. However, if cells are further illuminated for several h under Na+ stress, then full recovery takes much longer, and requires new protein synthesis. Electron transport assays using isolated membranes demonstrate that the immediate inhibition resulting from Na+ depletion involves the O2 evolving site, while the secondary effect requiring new protein synthesis occurs near the reaction center of Photosystem II. Experiments conducted at different pH values and in the absence of inorganic carbon demonstrate that within the short time duration of these experiments Na+ does not inhibit photosynthesis by restricting bicarbonate movement into the cells. These experiments extend previous results with other cyanobacteria which demonstrated that Ca2+ and Na+ stress cause reversible damage at a site near the reaction center of Photosystem II. The damage can be characterized as a primary ion effect at the oxygen evolving site and a secondary photoinhibition near the reaction center of Photosystem II.


Assuntos
Cianobactérias/metabolismo , Fotossíntese , Sódio/fisiologia , Bicarbonatos/metabolismo , Membrana Celular/metabolismo , Transporte de Elétrons , Luz , Oxigênio/metabolismo , Fotossíntese/efeitos dos fármacos , Fotossíntese/efeitos da radiação , Sódio/farmacologia , Espectrofotometria Atômica
13.
Lin Chuang Er Bi Yan Hou Ke Za Zhi ; 14(2): 70-1, 2000 Feb.
Artigo em Zh | MEDLINE | ID: mdl-12541479

RESUMO

OBJECTIVE: To improve the diagnosis and treatment of laryngeal malignant lymphoma. METHOD: Clinical features of 5 cases were reported and recent literatures were reviewed. RESULT: 2 cases presented with large ulcerated lesions and their laryngeal structure were destroyed, their prognosis were poor. Another 3 cases were local primary lesions, they were generally associated with a relatively short history of hoarseness and dysphagia and exhibited grey-white neoplasms with preferential involvement in the supraglottic parts of larynx, but non-ulcerated lesions, they were treated with operation and radiotherapy or chemotherapy or combinations. The prognosis were very well after 2 to 6 years follow up. CONCLUSION: It is important for the local primary lesion to be diagnosed correctly for the treatment and prognosis.


Assuntos
Neoplasias Laríngeas , Linfoma não Hodgkin , Adulto , Feminino , Seguimentos , Humanos , Neoplasias Laríngeas/diagnóstico , Neoplasias Laríngeas/terapia , Linfoma não Hodgkin/diagnóstico , Linfoma não Hodgkin/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico
14.
Zentralbl Bakteriol Mikrobiol Hyg B ; 178(3): 259-62, 1983 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6659745

RESUMO

The effect of PVNO treatment on human silicosis was observed in 7 cases over a period of 9 years lasting from 1965 to 1974. The drug was given intramuscularly and by way of inhalation, respectively. The comparison of the radiographs taken before, during and 3 years after the administration of PVNO showed that during treatment the tendency of fibrotic progression was delayed in 4 cases while 2 cases were slightly progressive, and one was markedly progressive, 3 years after discontinuation of the PVNO treatment, only one case remained stable, two cases were slightly and 4 cases markedly progressive. These observations indicate that PVNO treatment may have an effect on the delay and control of silicosis progression in a portion of patients, but after discontinuation of the treatment further progression is possible.


Assuntos
N-Óxido de Polivinilpiridina/uso terapêutico , Polivinil/uso terapêutico , Silicose/tratamento farmacológico , Esquema de Medicação , Seguimentos , Humanos , Injeções Intramusculares , N-Óxido de Polivinilpiridina/administração & dosagem , Radiografia , Silicose/diagnóstico por imagem
15.
Biochemistry ; 30(31): 7863-72, 1991 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-1651109

RESUMO

The psaC gene product from Synechococcus sp. PCC 7002 and the psaD gene product from Nostoc sp. PCC 8009 were synthesized in Escherichia coli and purified to homogeneity. Incubation of the PsaC apoprotein with the Synechoccus sp. PCC 6301 photosystem I core protein in the presence of FeCl3, Na2S, and beta-mercaptoethanol resulted in a time-dependent transition in the flash-induced absorption change from a 1.2-ms, P700+ FX- back-reaction to a long-lived, P700+ [FA/FB]- back-reaction. ESR studies showed that FB and FA were photoreduced about equally at 19 K, and while the resonances were shifted upfield, they remained as broad as in the free PsaC holoprotein. When the reconstituted complex was purified in a sucrose gradient containing 0.1% Triton X-100, most of the optical absorption transient reverted to that characteristic of the P700+ FX- back-reaction. Addition of purified PsaD to the incubation mixture led to a greater extent of recovery of electron flow to FA/FB for any given concentration of PsaC. ESR studies showed that FA, rather than FB, became the preferred electron acceptor at 19 K; moreover, the resonances moved upfield and sharpened to become nearly identical with those of a control photosystem I complex. When the sample was purified in a sucrose gradient containing 0.1% Triton X-100, the long-lived P700+ [FA/FB]- optical transient remained stable. Analysis by denaturing polyacrylamide gel electrophoresis showed that the PsaC and PsaD proteins had rebound to the photosystem I core. The data indicate that although PsaC can bind loosely, the presence of PsaD leads to a stable, isolatable photosystem I complex which is spectroscopically indistinguishable from the native complex. Since a PsaC1 fusion protein which contains an amino-terminal extension of five amino acids (MEHSM...) does not bind in the absence of PsaD [Zhao, J., et al. (1990) FEBS Lett. 276, 175-180], the N-terminus of the PsaC protein could provide a site of interaction with the photosystem I core. We propose that the binding of PsaC to the PsaA/PsaB heterodimer is potentiated by insertion of the FA/FB clusters into PsaC, and stabilized by the presence of PsaD.


Assuntos
Cianobactérias/metabolismo , Proteínas de Membrana , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Complexo de Proteína do Fotossistema I , Proteínas de Plantas/metabolismo , Proteínas/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Cianobactérias/genética , Espectroscopia de Ressonância de Spin Eletrônica , Escherichia coli/genética , Cinética , Luz , Dados de Sequência Molecular , Peso Molecular , Complexo de Proteínas do Centro de Reação Fotossintética/genética , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Plasmídeos , Ligação Proteica , Proteínas/genética , Proteínas/isolamento & purificação , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Mapeamento por Restrição
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