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J Biol Chem ; 2018 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-30425099


LATERAL ORGAN BOUNDARIES DOMAIN (LBD) proteins, a family of plant-specific transcription factors harboring a conserved LOB domain, are regulators of plant organ development. Recent studies have unraveled additional pivotal roles of the LBD protein family beyond defining lateral organ boundaries, such as pollen development and nitrogen metabolism. The structural basis for the molecular network of LBD-dependent processes remains to be deciphered. Here, we solved the first structure of the homodimeric LOB domain of Ramosa2 from wheat (TtRa2LD) to 1.9 Å resolution. Our crystal structure reveals structural features shared with other zinc-finger transcriptional factors, as well as some features unique to LBD proteins. Formation of the TtRa2LD homodimer relied on hydrophobic interactions of its coiled-coil motifs. Several specific motifs/domains of the LBD protein were also involved in maintaining its overall conformation. The intricate assembly within and between the monomers determined the precise spatial configuration of the two zinc fingers that recognize palindromic DNA sequences. Biochemical, molecular modeling, and small-angle X-ray scattering (SAXS) experiments indicated that dimerization is important for cooperative DNA binding and discrimination of palindromic DNA through a molecular calipers mechanism. Along with previously published data, this study enables us to establish an atomic-scale mechanistic model for LBD proteins as transcriptional regulators in plants.

Zhonghua Jie He He Hu Xi Za Zhi ; 30(8): 577-81, 2007 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-17988549


OBJECTIVE: To identify potential biomarkers related with lung cancer metastasis. METHODS: Conditional media proteins collected from a primary non-small cell lung cancer cell line (NSCLC) NCI-H226 and its brain metastatic subline H226Br were analyzed by SDS-PAGE and MALDI-TOF-MS. Twelve biomarkers were identified, of which LDHB was significantly up-regulated in H226Br cell and was further validated using ELISA in sera including 105 lung cancer samples, 41 pneumonia and pulmonary tuberculosis samples and 65 healthy samples. RESULTS: The levels of LDHB were specifically elevated in NSCLC sera [A value 0.485 (0 - 1.415)] compared with pneumonia and pulmonary tuberculosis [A value 0.187 (0 - 0.609), P < 0.01] and healthy group [A value, 0.159 (0 - 0.524), P < 0.01] and were progressively increased with the clinical stage. At the cutoff point 0.260 (A value) on the ROC curve, the sensitivity, specificity and total accuracy of LDHB were 81%, 70% and 76% respectively. CONCLUSION: These findings demonstrated that secretome could open up a possibility to identify novel biomarkers related with cancer occurrence and metastasis.

Biomarcadores Tumorais/sangue , Carcinoma de Células Escamosas/sangue , L-Lactato Desidrogenase/sangue , Neoplasias Pulmonares/sangue , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Meios de Cultivo Condicionados/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , L-Lactato Desidrogenase/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Proteômica/métodos , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/metabolismo , Tuberculose Pulmonar/patologia
Sci China C Life Sci ; 50(3): 305-11, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17609886


Two hundred and eighteen serum samples from 175 lung cancer patients and 43 healthy individuals were analyzed by using Surface Enhaced Laser Desorption/Ionization Time of Flight Mass Spectrome-try (SELDI-TOF-MS). The data analyzed by both Biomarker Wizardtrade mark and Biomarker Patternstrade mark software showed that a protein peak with the molecular weight of 11.6 kDa significantly increased in lung cancer. Meanwhile, the level of this biomarker was progressively increased with the clinical stages of lung cancer. The candidate biomarker was then obtained from tricine one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis by matching the molecular weight with peaks on WCX2 chips and was identified as Serum Amyloid A protein (SAA) by MALDI/MS-MS and database searching. It was further validated in the same serum samples by immunoprecipitation with commercial SAA antibody. To confirm the SAA differential expression in lung cancer patients, the same set of serum samples was measured by ELISA assay. The result showed that at the cutoff point 0.446 (OD value) on the Receiver Operating Characteristic (ROC) curve, SAA could better discriminate lung cancer from healthy individuals with sensitivity of 84.1% and specificity of 80%. These findings demonstrated that SAA could be characterized as a biomarker related to pathological stages of lung cancer.

Biomarcadores Tumorais/sangue , Neoplasias Pulmonares/sangue , Proteína Amiloide A Sérica/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , Neoplasias Pulmonares/patologia , Peso Molecular , Estadiamento de Neoplasias , Valores de Referência , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
Biomed Environ Sci ; 20(1): 24-32, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17458138


OBJECTIVE: To construct a database of human lung squamous carcinoma cell line NCI-H226 and to facilitate discovery of novel subtypes markers of lung cancer. METHOD: Proteomic technique was used to analyze human lung squamous carcinoma cell line NCI-H226. The proteins of the NCI-H226 cells were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. RESULTS: The results showed that a good reproducibility of the 2-D gel pattern was attained. The position deviation of matched spots among three 2-D gels was 1.95 +/- 0.53 mm in the isoelectric focusing direction, and 1.73 +/- 0.45 mm in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis direction. One hundred and twenty-seven proteins, including enzymes, signal transduction proteins, structure proteins, transport proteins, etc. were characterized, of which, 29 identified proteins in NCI-H226 cells were reported for the first time to be involved in lung cancer carcinogenesis. CONCLUSION: The information obtained from this study could provide some valuable clues for further study on the carcinogenetic mechanism of different types of lung cancer, and may help us to discover some potential subtype-specific biomarkers of lung cancer.

Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/química , Linhagem Celular Tumoral , Neoplasias Pulmonares/química , Proteínas de Neoplasias/análise , Bases de Dados Factuais , Eletroforese em Gel Bidimensional , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem
Guang Pu Xue Yu Guang Pu Fen Xi ; 23(1): 187-91, 2003 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-12940004


The main purpose of quasar recognition is to determine the observed quasar spectrum's redshift value. Previously the template of quasar rest frame in the literature was basically constructed based on astronomers' hypotheses. Due to the inaccuracy of such a template, it is hard to determine the redshift value by matching the observed quasar spectrum with the template directly. This paper's main contributions are two-fold: Firstly, the template in our paper is constructed by the principal component analysis (PCA) method from some selected spectra with known redshift values, hence the obtained template is more realistic. Secondly, a 2D standard Hough transform, rather than a 1D Hough transform, is used. This is because although only redshift needs to be determined in our system, based on our observations, the magnitude of emission peak is also changed, hence a new parameter, namely scale parameter, is also introduced to the Hough transform to enhance the reliability of the recognition. The experiments show that the proposed technique is workable and the correct recognition rate can reach about as high as 90%.