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Complex Bound (complex + bound)
Selected AbstractsTristetraprolin recruits functional mRNA decay complexes to ARE sequencesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2007Heidi H. Hau Abstract AU-rich elements (AREs) in the 3, untranslated region (UTR) of numerous mammalian transcripts function as instability elements that promote rapid mRNA degradation. Tristetraprolin (TTP) is an ARE-binding protein that promotes rapid mRNA decay through mechanisms that are poorly understood. A 31 nucleotide ARE sequences from the TNF-alpha 3, UTR promoted TTP-dependent mRNA decay when it was inserted into the 3, UTR of a beta-globin reporter transcript, indicating that this short sequence was sufficient for TTP function. We used a gel shift assay to identify a TTP-containing complex in cytoplasmic extracts from TTP-transfected HeLa cells that bound specifically to short ARE sequences. This TTP-containing complex also contained the 5,,3, exonuclease Xrn1 and the exosome component PM-scl75 because it was super-shifted with anti-Xrn1 or anti-PMscl75 antibodies. RNA affinity purification verified that these proteins associated specifically with ARE sequences in a TTP-dependent manner. Using a competition binding assay, we found that the TTP-containing complex bound with high affinity to short ARE sequences from GM-CSF, IL-3, TNF-alpha, IL-2, and c-fos, but did not bind to a U-rich sequence from c-myc, a 22 nucleotide poly U sequence or a mutated GM-CSF control sequence. High affinity binding by the TTP-containing complex correlated with TTP-dependent deadenylation and decay of capped, polyadenylated transcripts in a cell-free mRNA decay assay, suggesting that the TTP-containing complex was functional. These data support a model whereby TTP functions to enhance mRNA decay by recruiting components of the cellular mRNA decay machinery to the transcript. J. Cell. Biochem. 100: 1477,1492, 2007. © 2006 Wiley-Liss, Inc. [source] Characterization of cis elements of the probasin promoter necessary for prostate-specific gene expression,THE PROSTATE, Issue 9 2010JianFeng Zhang Abstract BACKGROUND The androgen-regulated probasin (PB) promoter has been used extensively to target transgenes to the prostate in transgenic mice; however, limited data exist on the mechanism that dictates prostate-specific gene expression. Tissue-specific gene expression involves synergistic effects among transcription factors associated in a complex bound to cis -acting DNA elements. METHODS Using comprehensive linker scan mutagenesis, enzyme mobility shift and supershift assays, chromatin immunoprecipitation, and transgenic animal studies, we have extensively characterized the prostate-specific PB promoter. RESULTS We identified a series of nonreceptor transcription factors that are bound to the prostate-specific rat PB promoter. These factors include several ubiquitously distributed proteins known to participate in steroid receptor-mediated transcription. In addition, we identified two tissue-specific DNA elements that are crucial in directing prostate-specific PB expression, and confirmed the functional importance of both elements in transgenic animal studies. These two elements are functionally interchangeable and can be bound by multiple protein complexes, including the forkhead transcription factor FoxA1, a "pioneer factor" that has a restricted distribution to some cells type that are ectoderm and endoderm in origin. Using transgenic mice, we further demonstrate that the minimal PB promoter region (,244/,96,bp) that encompasses these tissue-specific elements results in prostate-specific gene expression in transgenic mice, contains androgen receptor and FoxA1-binding sites, as well as ubiquitous transcription factor binding sites. CONCLUSION We propose that these sequence-specific DNA-binding proteins, including tissue-restricted and ubiquitous factors, create the first level of transcriptional control, which responds to intracellular pathways that directs prostate-specific gene expression. Prostate 70: 934,951, 2010. © 2010 Wiley-Liss, Inc. [source] In situ ESR study of gold supported on NaY zeoliteASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Z. Qu Abstract Electron spin resonance (ESR) spectroscopy was used to study the anchoring of a Au complex and gold nanoparticles in NaY type zeolites. The complex of Au(II) with two nitrogen atoms of two ethylenediamine ligands [giso = 2.053, A (Au) = 16.4 G, A (N) = 15.0 G.] in the supercage of the zeolite and conduction electron spin resonance (CESR) of gold particles with 1.56-nm diameter (g = 2.064) were observed. Their formation and stability were related with the gold concentration and the pre-treatment conditions. The small gold particles stabilized in the supercage of zeolite were formed in the samples with low gold concentration after oxygen pre-treatment. The confinement in the zeolite pores obviously prevents the Au(II) complex bound to two nitrogen ligands from undergoing disproportionation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Crystallization and preliminary X-ray crystallographic analysis of Thermus thermophilus transcription elongation complex bound to Gfh1ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010Shunsuke Tagami RNA polymerase (RNAP) elongates RNA by iterative nucleotide-addition cycles (NAC). A specific structural state (or states) of RNAP may be the target of transcription elongation factors. Gfh1, a Thermus thermophilus Gre-family protein, inhibits NAC. To elucidate which RNAP structural state Gfh1 associates with, the T. thermophilus RNAP elongation complex (EC) was cocrystallized with Gfh1. Of the 70 DNA/RNA scaffolds tested, two (for EC1 and EC2) were successfully crystallized. In the presence of Gfh1, EC1 and EC2 yielded crystals belonging to space group P21 with similar unit-cell parameters (crystals 1 and 2, respectively). X-ray diffraction data sets were obtained at 3.6 and 3.8,Å resolution, respectively. [source] | ||||||||||