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Nucleic Acid-binding Protein (nucleic + acid-binding_protein)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Effective elimination of nucleic acids from bacterial protein samples for optimized blue native polyacrylamide gel electrophoresis

ELECTROPHORESIS, Issue 14 2009
Jingdan Liang
Abstract Nucleic acids remaining within bacterial protein samples from Streptomyces lividans and Escherichia coli were found to interfere significantly with blue native polyacrylamide gel electrophoresis (BN-PAGE), a technique used frequently for analyzing bacterial protein complexes in proteomics studies. We have used ultracentrifugation and/or precipitation of cell lysates with streptomycin sulfate to eliminate nucleic acids from total and/or membrane protein samples. Nucleic acid-binding proteins were first enriched by precipitation with streptomycin sulfate, and contaminating nucleic acids were then eliminated by precipitation by adding polyethyleneimine. The performance of BN-PAGE was found to be dramatically improved by these sample preparation steps. [source]

Expression of zonula occludens-1 (ZO-1) and the transcription factor ZO-1-associated nucleic acid-binding protein (ZONAB),MsY3 in glial cells and colocalization at oligodendrocyte and astrocyte gap junctions in mouse brain

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2005
Mihai C. Penes
Abstract The PDZ domain-containing protein zonula occludens-1 (ZO-1) interacts with several members of the connexin (Cx) family of gap junction-forming proteins and has been localized to gap junctions, including those containing Cx47 in oligodendrocytes. We now provide evidence for ZO-1 expression in astrocytes in vivo and association with astrocytic connexins by confocal immunofluorescence demonstration of ZO-1 colocalization with astrocytic Cx30 and Cx43, and by ZO-1 coimmunoprecipitation with Cx30 and Cx43. Evidence for direct interaction of Cx30 with ZO-1 was obtained by pull-down assays that indicated binding of Cx30 to the second of the three PDZ domains in ZO-1. Further, we investigated mouse Y-box transcription factor MsY3, the canine ortholog of which has been termed ZO-1-associated nucleic acid-binding protein (ZONAB) and previously reported to interact with ZO-1. By immunofluorescence using specific antimouse ZONAB antibody, ZONAB was found to be associated with oligodendrocytes throughout mouse brain and spinal cord, and to be colocalized with oligodendrocytic Cx47 and Cx32 as well as with astrocytic Cx43. Our results extend the CNS cell types that express the multifunctional protein ZO-1, demonstrate an additional connexin (Cx30) that directly interacts with ZO-1, and show for the first time the association of a transcription factor (ZONAB) with ZO-1 localized to oligodendrocyte and astrocyte gap junctions. Given previous observations that ZONAB and ZO-1 in combination regulate gene expression, our results suggest roles of glial gap junction-mediated anchoring of signalling molecules in a wide variety of glial homeostatic processes. [source]

Mass spectrometric analysis of microtubule co-sedimented proteins from rat brain

GENES TO CELLS, Issue 4 2008
Tatsuhiko Sakamoto
Microtubules (MTs) play crucial roles in a variety of cell functions, such as mitosis, vesicle transport and cell motility. MTs also compose specialized structures, such as centrosomes, spindles and cilia. However, molecular mechanisms of these MT-based functions and structures are not fully understood. Here, we analyzed MT co-sedimented proteins from rat brain by tandem mass spectrometry (MS) upon ion exchange column chromatography. We identified a total of 391 proteins. These proteins were grouped into 12 categories: 57 MT cytoskeletal proteins, including MT-associated proteins (MAPs) and motor proteins; 66 other cytoskeletal proteins; 4 centrosomal proteins; 10 chaperons; 5 Golgi proteins; 7 mitochondrial proteins; 62 nucleic acid-binding proteins; 14 nuclear proteins; 13 ribosomal proteins; 28 vesicle transport proteins; 83 proteins with diverse function and/or localization; and 42 uncharacterized proteins. Of these uncharacterized proteins, six proteins were expressed in cultured cells, resulting in the identification of three novel components of centrosomes and cilia. Our present method is not specific for MAPs, but is useful for identifying low abundant novel MAPs and components of MT-based structures. Our analysis provides an extensive list of potential candidates for future study of the molecular mechanisms of MT-based functions and structures. [source]

Acquisition of double-stranded DNA-binding ability in a hybrid protein between Escherichia coli CspA and the cold shock domain of human YB-1

MOLECULAR MICROBIOLOGY, Issue 3 2000
Nan Wang
Escherichia coli CspA, a major cold shock protein, is dramatically induced upon temperature downshift. As it binds co-operatively to single-stranded DNA (ssDNA) and RNA without apparent sequence specificity, it has been proposed that CspA acts as an RNA chaperone to facilitate transcription and translation at low temperature. CspA consists of a five-stranded ,-barrel structure containing two RNA-binding motifs, RNP1 and RNP2. Eukaryotic Y-box proteins, such as human YB-1, are a family of nucleic acid-binding proteins that share a region of high homology with CspA (43% identity), termed the cold shock domain (CSD). Their cellular functions are very diverse and are associated with growth-related processes. Here, we replaced the six-residue loop region of CspA between the ,3 and ,4 strands with the corresponding region of the CSD of human YB-1 protein. The resulting hybrid protein became capable of binding to double-stranded DNA (dsDNA) in addition to ssDNA and RNA. The dsDNA-binding ability of an RNP1 point mutant (F20L) of the hybrid was almost unchanged. On the other hand, the dsDNA-binding ability of the hybrid protein was abolished in high salt concentrations in contrast to its ssDNA-binding ability. These results indicate that the loop region between the ,3 and ,4 strands of Y-box proteins, which is a little longer and more basic than that of CspA, plays an important role in their binding to dsDNA. [source]