The UL97 protein of human cytomegalovirus (HCMV, or HHV-5 (human herpesvirus 5)), is a kinase that phosphorylates the cellular retinoblastoma (Rb) tumor suppressor and lamin A/C proteins that are ...also substrates of cellular cyclin-dependent kinases (Cdks). A functional complementation assay has further shown that UL97 has authentic Cdk-like activity. The other seven human herpesviruses each encode a kinase with sequence and positional homology to UL97. These UL97-homologous proteins have been termed the conserved herpesvirus protein kinases (CHPKs) to distinguish them from other human herpesvirus-encoded kinases. To determine if the Cdk-like activities of UL97 were shared by all of the CHPKs, we individually expressed epitope-tagged alleles of each protein in human Saos-2 cells to test for Rb phosphorylation, human U-2 OS cells to monitor nuclear lamina disruption and lamin A phosphorylation, or S. cerevisiae cdc28-13 mutant cells to directly assay for Cdk function. We found that the ability to phosphorylate Rb and lamin A, and to disrupt the nuclear lamina, was shared by all CHPKs from the beta- and gamma-herpesvirus families, but not by their alpha-herpesvirus homologs. Similarly, all but one of the beta and gamma CHPKs displayed bona fide Cdk activity in S. cerevisiae, while the alpha proteins did not. Thus, we have identified novel virally-encoded Cdk-like kinases, a nomenclature we abbreviate as v-Cdks. Interestingly, we found that other, non-Cdk-related activities reported for UL97 (dispersion of promyelocytic leukemia protein nuclear bodies (PML-NBs) and disruption of cytoplasmic or nuclear aggresomes) showed weak conservation among the CHPKs that, in general, did not segregate to specific viral families. Therefore, the genomic and evolutionary conservation of these kinases has not been fully maintained at the functional level. Our data indicate that these related kinases, some of which are targets of approved or developmental antiviral drugs, are likely to serve both overlapping and non-overlapping functions during viral infections.
Messenger RNAs are monitored for errors that arise during gene expression by a mechanism called RNA surveillance, with the result that most mRNAs that cannot be translated along their full length are ...rapidly degraded. This ensures that truncated proteins are seldom made, reducing the accumulation of rogue proteins that might be deleterious. The pathway leading to accelerated mRNA decay is referred to as nonsense-mediated mRNA decay (NMD). The proteins that catalyze steps in NMD in yeast serve two roles, one to monitor errors in gene expression and the other to control the abundance of endogenous wild-type mRNAs as part of the normal repertoire of gene expression. The NMD pathway has a direct impact on hundreds of genetic disorders in the human population, where about a quarter of all known mutations are predicted to trigger NMD.
Nonsense-mediated mRNA decay (NMD) is a eukaryotic mechanism of RNA surveillance that selectively eliminates aberrant transcripts coding for potentially deleterious proteins. NMD also functions in ...the normal repertoire of gene expression. In Saccharomyces cerevisiae, hundreds of endogenous RNA Polymerase II transcripts achieve steady-state levels that depend on NMD. For some, the decay rate is directly influenced by NMD (direct targets). For others, abundance is NMD-sensitive but without any effect on the decay rate (indirect targets). To distinguish between direct and indirect targets, total RNA from wild-type (Nmd(+)) and mutant (Nmd(-)) strains was probed with high-density arrays across a 1-h time window following transcription inhibition. Statistical models were developed to describe the kinetics of RNA decay. 45% +/- 5% of RNAs targeted by NMD were predicted to be direct targets with altered decay rates in Nmd(-) strains. Parallel experiments using conventional methods were conducted to empirically test predictions from the global experiment. The results show that the global assay reliably distinguished direct versus indirect targets. Different types of targets were investigated, including transcripts containing adjacent, disabled open reading frames, upstream open reading frames, and those prone to out-of-frame initiation of translation. Known targeting mechanisms fail to account for all of the direct targets of NMD, suggesting that additional targeting mechanisms remain to be elucidated. 30% of the protein-coding targets of NMD fell into two broadly defined functional themes: those affecting chromosome structure and behavior and those affecting cell surface dynamics. Overall, the results provide a preview for how expression profiles in multi-cellular eukaryotes might be impacted by NMD. Furthermore, the methods for analyzing decay rates on a global scale offer a blueprint for new ways to study mRNA decay pathways in any organism where cultured cell lines are available.
In eukaryotes, mRNAs are monitored for errors in gene expression by RNA surveillance where untranslatable mRNAs are selectively degraded by the nonsense-mediated mRNA decay (NMD) pathway. Depending ...on the organism, three to seven genes are required for NMD. Besides RNA surveillance, the genes required for NMD serve a second purpose by controlling the overall abundance of a substantial fraction of the transcriptome.
The Saccharomyces cerevisiae SEN1 gene codes for a nuclear, ATP-dependent helicase which is embedded in a complex network of protein-protein interactions. Pleiotropic phenotypes of mutations in SEN1 ...suggest that Sen1 functions in many nuclear processes, including transcription termination, DNA repair, and RNA processing. Sen1, along with termination factors Nrd1 and Nab3, is required for the termination of noncoding RNA transcripts, but Sen1 is associated during transcription with coding and noncoding genes. Sen1 and Nrd1 both interact directly with Nab3, as well as with the C-terminal domain (CTD) of Rpb1, the largest subunit of RNA polymerase II. It has been proposed that Sen1, Nab3, and Nrd1 form a complex that associates with Rpb1 through an interaction between Nrd1 and the Ser5-phosphorylated (Ser5-P) CTD. To further study the relationship between the termination factors and Rpb1, we used two-hybrid analysis and immunoprecipitation to characterize sen1-R302W, a mutation that impairs an interaction between Sen1 and the Ser2-phosphorylated CTD. Chromatin immunoprecipitation indicates that the impairment of the interaction between Sen1 and Ser2-P causes the reduced occupancy of mutant Sen1 across the entire length of noncoding genes. For protein-coding genes, mutant Sen1 occupancy is reduced early and late in transcription but is similar to that of the wild type across most of the coding region. The combined data suggest a handoff model in which proteins differentially transfer from the Ser5- to the Ser2-phosphorylated CTD to promote the termination of noncoding transcripts or other cotranscriptional events for protein-coding genes.
Recent clinical experience with migraine surgery has demonstrated both the safety and the efficacy of operative decompression of the peripheral nerves in the face, head, and neck for the alleviation ...of migraine symptoms. Because of the perceived novelty of these procedures, and the paranoia surrounding a theoretical loss of clinical territory, neurologists have condemned the field of migraine surgery. The Patient Safety Subcommittee of the American Society of Plastic Surgeons ventured to investigate the published safety track record of migraine surgery in the existing body of literature.
A comprehensive review of the relevant published literature was performed. The relevant databases and literature libraries were reviewed from the date of their inception through early 2018. These articles were reviewed and their findings analyzed.
Thirty-nine published articles were found that demonstrated a substantial, extensively replicated body of data that demonstrate a significant reduction in migraine headache symptoms and frequency (even complete elimination of headache pain) following trigger-site surgery.
Migraine surgery is a valid method of treatment for migraine sufferers when performed by experienced plastic surgeons following a methodical protocol. These operations are associated with a high level of safety. The safety and efficacy of migraine surgery should be recognized by plastic surgeons, insurance companies, and the neurology societies.
Purpose: The U.S. Food and Drug Administration indications for cochlear implantation in children is currently 9 months of age and older for children with bilateral profound sensorineural hearing loss ...(SNHL). Studies have shown that earlier activation of a cochlear implant (CI) can lead to better spoken language outcomes. As auditory skills are a precursor to the development of spoken language, this study was developed to investigate the influence of age at CI activation on auditory skill acquisition in young children. A secondary aim was to describe the auditory skills of children implanted prior to 9 months of age as compared to children with older ages of activation. Method: Functional Listening Index (FLI) scores obtained during routine clinical visits were reviewed for 78 pediatric CI recipients with congenital bilateral profound hearing loss who were activated before 2 years of age. A linear mixed-effects model assessed the effect of age at CI activation on cumulative FLI scores over time. Results: There was a significant interaction between age at activation and chronological age at the time of evaluation, indicating that children with earlier access to sound achieved a greater number of auditory skills than those with later CI activations when measured at the same chronological age. Children activated before the age of 9 months approximated scores expected of children with typical hearing, whereas children activated between 9 and 24 months of age did not. Conclusions: Younger age at CI activation is associated with increased auditory skills over time. Children who undergo cochlear implantation and CI activation before 9 months achieve more auditory skills by 4 years of age than children who are activated at later ages. These data suggest that reducing the approved age at cochlear implantation for children with congenital bilateral profound SNHL may support optimal auditory skill acquisition.
Abstract Purpose To analyze longitudinal changes in each subscale of a quality of life (QOL) measure and to explore their relationships to effective QOL predictors in breast cancer surgery patients. ...Patients and methods This prospective study analyzed 172 patients at two tertiary academic hospitals. All patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its supplementary breast cancer measure (QLQ-BR23) at baseline and at 1 and 2 years postoperatively. The 95% confidence intervals for differences in responsiveness estimates were derived by bootstrap estimation. Scores derived by these instruments were interpreted by generalized estimating equation (GEE) before and after surgery. Results A 2-year follow-up survey of the examined population revealed significant ( P < 0.05) improvement in each QOL subscale. In both postoperative surveys, effect size was largest in the QLQ subscales for patients who had received mastectomy with reconstruction and lowest in those who had received modified radical mastectomy. After adjusting for time effects and baseline predictors, GEE approaches revealed the following explanatory variables for QOL: time, type of surgical procedure, age, chemotherapy, radiotherapy, hormone therapy, and preoperative functional status. Conclusions When evaluating QOL after breast cancer surgery, several factors other than the surgery itself should be considered. Patients should also be advised that their postoperative QOL might depend not only on the success of their operations, but also on their preoperative functional status.
The CDF Silicon Vertex Trigger Ashmanskas, Bill; Barchiesi, A.; Bardi, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
1
Journal Article
Recenzirano
The Collider Detector at Fermilab (CDF) experiment's Silicon Vertex Trigger (SVT) is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a
15
μs
...pipeline. SVT's
35
μm
impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common interboard data link, and a universal “Merger” board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.
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