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Biomedical subjects

Lucy Lee

Publications and source records attributed to Lucy Lee.

26 records · Page 2Linked to original sources
PubMed2003

A report of the functional connectivity workshop, Dusseldorf 2002.

This report provides a commentary on the issues presented and discussed at the recent "Functional Brain Connectivity" workshop, held in Dusseldorf, Germany. The workshop brought together researchers using different approaches to study connectivity in the brain, providing them with an opportunity to share conceptual, mathematical, and experimental ideas and to develop strategies and collaborations for future work on functional integration. The main themes that emerged included: (1) the importance of anatomical knowledge in understanding functional interactions the brain; (2) the need to establish common definitions for terms used across disciplines; (3) the need to develop a satisfactory framework for inferring causality from functional imaging and EEG/MEG data; (4) the importance of analytic tools that capture the dynamics of neural interactions; and (5) the role of experimental paradigms that exploit the functional imaging of perturbations to cortical interactions.

Animals↗
PubMed2003

Characterization of the chromosomal binding sites and dimerization partners of the viral oncoprotein Meq in Marek's disease virus-transformed T cells.

Marek's disease virus (MDV) is an acute transforming alphaherpesvirus that causes T-cell lymphomas in chickens. We previously reported the identification of a putative oncogene, meq, that is encoded only by the oncogenic serotype of MDV. The gene product, Meq, is a latent protein that is consistently expressed in MDV-transformed lymphoblastoid cells and tumor cells. Meq has a bZIP (basic leucine zipper) structure resembling the family of Jun/Fos. The mechanism whereby Meq transforms T cells remains poorly understood. In this study, we explored the properties of Meq as a transcriptional factor. We analyzed Meq's dimerization partners and its target genes in MSB-1, an MDV-transformed T-cell line. By using in vitro assays, we first demonstrated Meq's potential to dimerize with a variety of bZIP proteins. We then identified c-Jun as the primary dimerization partner of Meq. Both are found to be colocalized in the nucleus and corecruited to promoters with AP-1 sequences. By using chromatin immunoprecipitation (ChIP), we scanned the entire MDV genome for Meq binding sites and found three regions that were enriched with Meq binding: the MDV lytic replication origin, the promoter for Meq, and the promoter for ICP4. Transactivation assays using the above promoters showed that Meq/Meq homodimers exhibited repression activity, whereas Meq/Jun heterodimers showed activation. Finally, we were able to show by ChIP that Meq is recruited to the interleukin-2 promoter in a region encompassing an AP-1 site. Thus, in addition to providing general knowledge about the transcriptional properties of Meq, our studies revealed for the first time the ability of Meq to interact with the latent MDV and host genomes. Our data suggest, therefore, a role for Meq in viral genome regulation during latency, in addition to its putative causal role in T-cell transformation.

Animals↗
PubMed2003

The Functional Brain Connectivity Workshop: report and commentary.

This report summarizes the presentations and discussions at a recent workshop entitled 'Functional Brain Connectivity', held in Düsseldorf, Germany. The aims of the workshop were to bring together researchers using different approaches to study connectivity in the brain, to enable them to share conceptual, mathematical and experimental ideas and to develop strategies for future work on functional integration. The main themes that emerged included: (1) the importance of anatomical knowledge in understanding functional interactions the brain; (2) the need to establish common definitions for terms used across disciplines; (3) the need to develop a satisfactory framework for inferring causality from functional imaging and electroencephalographic/magneto-encephalographic data; (4) the importance of analytic tools that capture the dynamics of neural interactions; and (5) the role of experimental paradigms that exploit the functional imaging of perturbations to cortical interactions.

Animals↗
PubMed2002

Ligand-induced conformational and structural dynamics changes in Escherichia coli cyclic AMP receptor protein.

Cyclic AMP receptor protein (CRP) regulates the expression of a large number of genes in E. coli. It is activated by cAMP binding, which leads to some yet undefined conformational changes. These changes do not involve significant redistribution of secondary structures. A potential mechanism of activation is a ligand-induced change in structural dynamics. Hence, the cAMP-mediated conformational and structural dynamics changes in the wild-type CRP were investigated using hydrogen-deuterium exchange and Fourier transform infrared spectroscopy. Upon cAMP binding, the two functional domains within the wild-type CRP undergo conformational and structural dynamics changes in two opposite directions. While the smaller DNA-binding domain becomes more flexible, the larger cAMP-binding domain shifts to a less dynamic conformation, evidenced by a faster and a slower amide H-D exchange, respectively. To a lesser extent, binding of cGMP, a nonfunctional analogue of cAMP, also stabilizes the cAMP-binding domain, but it fails to mimic the relaxation effect of cAMP on the DNA-binding domain. Despite changes in the conformation and structural dynamics, cAMP binding does not alter significantly the secondary structural composition of the wild-type CRP. The apparent difference between functional and nonfunctional analogues of cAMP is the ability of cAMP to effect an increase in the dynamic motions of the DNA binding domain.

Binding Sites↗
PubMed2002

[Antigen analysis of envelope gene products of avian leukosis virus subgroup J].

Envelope glycoprotein of avian leukosis virus Subgroup J (ALV-J) determines the host range of virus infection and cross-neutralization patterns. The truncated envelope genes of avian lecukosis virus subgroup J (ALV-J) were amplified by PCR and cloned them into pGEX-5X-3 vector for expressing envGST-fusion protein. Western blot analysis results showed that the products of truncated env gene expressed in Escherichia coli could reacted with G2, JE9 and I45 monoclonal antibodies (Mabs) specific to envelope protein of ALV-J. Using different Mabs to map the epitopes in the expressed truncated gp85 GST fusion protein, the results showed that Mab G2 and JE9 antibodies recognizing epitope in gp85 was localized between amino acid 65-155. Mab I45 reacted with the epitope at the location of amino acid 156-233. It indicated that the specificity of subgroup J virus is determined by the gp85 peptide since GST-gp85 protein expressed in Escherichia coli is not glycosylated.

Antibodies, Monoclonal↗