58 research outputs found
Unconstraining the Unhiggs
We investigate whether or not perturbative unitarity is preserved in the
Unhiggs model for the scattering process of heavy quarks and longitudinal gauge
bosons . With the Yukawa coupling given in the
original formulation of the Unhiggs model, the model preserves unitarity for
Unhiggs scaling dimensions . We examine the LHC phenomenology that
is implied by the Unhiggs model in this parameter range in detail and discuss
to what extent the LHC can test if an excess is measured in the
phenomenologically clean channel in the future or if the LHC measurement
remains consistent with the background. We then make use of the AdS/CFT
correspondence to derive a new Yukawa coupling that is conformally invariant at
high energies, and show that with this Yukawa coupling the theory is unitary
for .Comment: 19 pages, 10 figures; typos corrected, version published by PR
Regulation of transcription termination in the nematode Caenorhabditis elegans
The current predicted mechanisms that describe RNA polymerase II (pol II) transcription termination downstream of protein expressing genes fail to adequately explain, how premature termination is prevented in eukaryotes that possess operon-like structures. Here we address this issue by analysing transcription termination at the end of single protein expressing genes and genes located within operons in the nematode Caenorhabditis elegans. By using a combination of RT-PCR and ChIP analysis we found that pol II generally transcribes up to 1 kb past the poly(A) sites into the 3′ flanking regions of the nematode genes before it terminates. We also show that pol II does not terminate after transcription of internal poly(A) sites in operons. We provide experimental evidence that five randomly chosen C. elegans operons are transcribed as polycistronic pre-mRNAs. Furthermore, we show that cis-splicing of the first intron located in downstream positioned genes in these polycistronic pre-mRNAs is critical for their expression and may play a role in preventing premature pol II transcription termination
An essential role for Clp1 in assembly of polyadenylation complex CF IA and Pol II transcription termination
Polyadenylation is a co-transcriptional process that modifies mRNA 3′-ends in eukaryotes. In yeast, CF IA and CPF constitute the core 3′-end maturation complex. CF IA comprises Rna14p, Rna15p, Pcf11p and Clp1p. CF IA interacts with the C-terminal domain of RNA Pol II largest subunit via Pcf11p which links pre-mRNA 3′-end processing to transcription termination. Here, we analysed the role of Clp1p in 3′ processing. Clp1p binds ATP and interacts in CF IA with Pcf11p only. Depletion of Clp1p abolishes transcription termination. Moreover, we found that association of mutations in the ATP-binding domain and in the distant Pcf11p-binding region impair 3′-end processing. Strikingly, these mutations prevent not only Clp1p-Pcf11p interaction but also association of Pcf11p with Rna14p-Rna15p. ChIP experiments showed that Rna15p cross-linking to the 3′-end of a protein-coding gene is perturbed by these mutations whereas Pcf11p is only partially affected. Our study reveals an essential role of Clp1p in CF IA organization. We postulate that Clp1p transmits conformational changes to RNA Pol II through Pcf11p to couple transcription termination and 3′-end processing. These rearrangements likely rely on the correct orientation of ATP within Clp1p
XAB2, a novel tetratricopeptide repeat protein, involved in transcription-coupled repair and transcription.
Nucleotide excision repair is a highly versatile DNA repair system responsible for elimination of a wide variety of lesions from the genome. It is comprised of two subpathways: transcription-coupled repair that accomplishes efficient removal of damage blocking transcription and global genome repair. Recently, the basic mechanism of global genome repair has emerged from biochemical studies. However, little is known about transcription-coupled repair in eukaryotes. Here we report the identification of a novel protein designated XAB2 (XPA-binding protein 2) that was identified by virtue of its ability to interact with XPA, a factor central to both nucleotide excision repair subpathways. The XAB2 protein of 855 amino acids consists mainly of 15 tetratricopeptide repeats. In addition to interacting with XPA, immunoprecipitation experiments demonstrated that a fraction of XAB2 is able to interact with the transcription-coupled repair-specific proteins CSA and CSB as well as RNA polymerase II. Furthermore, antibodies against XAB2 inhibited both transcription-coupled repair and transcription in vivo but not global genome repair when microinjected into living fibroblasts. These results indicate that XAB2 is a novel component involved in transcription-coupled repair and transcription
A Functional Interaction between the Survival Motor Neuron Complex and RNA Polymerase II
The Acute Myeloid Leukemia-Associated Protein, Dek, Forms a Splicing-Dependent Interaction with Exon-Product Complexes
Role of the Modular Domains of SR Proteins in Subnuclear Localization and Alternative Splicing Specificity
Three-Dimensional Visualization of Transcription Sites and Their Association with Splicing Factor–Rich Nuclear Speckles
Transcriptional termination in the Balbiani ring 1 gene is closely coupled to 3'-end formation and excision of the 3'-terminal intron
Bioengineering of Human Fetal Tissues For Clinical Use
Cultured primary fetal cells from one organ donation could possibly meet the exigent
and stringent technical aspects for development of therapeutic products. These cell types
have fewer technological limitations for cellular proliferation capacity (simple culture
conditions) and maintenance of differentiated phenotype, and they also have low
probability for transmission of communicable diseases. Master and Working Cell Banks
(MCB, WCB) can be obtained from one fetal organ donation, permitting multiple tissues
(skin, bone, cartilage, muscle and intervertebral disc) to be processed in short periods of
time with identical methods to assure a stringent tracing of the processes for the
production of standardized therapeutic agents. Clinical use of biologics from embryo and
fetal tissues is relatively new and current legislation and ethics have some differences
between countries to date. In addition, specific cell delivery systems for each tissue type
can be adapted to the clinical application. Since it is the intention that banked primary
fetal cells enhance the prospective treatment of hundreds of thousands of patients with
only one organ donation, it is imperative to show consistency, traceability and safety of
the processes including donor tissue selection, cell banking, cell testing and growth of
cells in out-scaling for the preparation of bio-engineered products for clinical application
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