289 research outputs found
Delineation of RAID1, the RACK1 interaction domain located within the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5
Background
The cyclic AMP specific phosphodiesterase, PDE4D5 interacts with the Ξ²-propeller protein RACK1 to form a signaling scaffold complex in cells. Two-hybrid analysis of truncation and mutant constructs of the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5 were used to define a domain conferring interaction with the signaling scaffold protein, RACK1.
Results
Truncation and mutagenesis approaches showed that the RACK1-interacting domain on PDE4D5 comprised a cluster of residues provided by Asn-22/Pro-23/Trp-24/Asn-26 together with a series of hydrophobic amino acids, namely Leu-29, Val-30, Leu-33, Leu-37 and Leu-38 in a 'Leu-Xaa-Xaa-Xaa-Leu' repeat. This was done by 2-hybrid analyses and then confirmed in biochemical pull down analyses using GST-RACK1 and mutant PDE4D5 forms expressed in COS cells. Mutation of Arg-34, to alanine, in PDE4D5 attenuated its interaction with RACK1 both in 2-hybrid screens and in pull down analyses. A 38-mer peptide, whose sequence reflected residues 12 through 49 of PDE4D5, bound to RACK1 with similar affinity to native PDE4D5 itself (Ka circa 6 nM).
Conclusions
The RACK1 Interaction Domain on PDE4D5, that we here call RAID1, is proposed to form an amphipathic helical structure that we suggest may interact with the C-terminal Ξ²-propeller blades of RACK1 in a manner akin to the interaction of the helical G-Ξ³ signal transducing protein with the Ξ²-propeller protein, G-Ξ²
Radical palliative surgery: new limits to pursue
This case report describes the radical subtotal palliative resection of a massive recurrent desmoid tumor encompassing the abdomen, pelvis, and groin in a child who was 13Β years old at the time of initial resection. Given the extensive distribution of the tumor en bloc resection, which is the standard treatment of desmoid tumors, would have meant performing a hemipelvectomy and repair of a large abdominal wall defect, likely with skin grafts and mesh. The patientβs personal goals however were to alleviate the pain and limited mobility that would allow her to re-attend high school and appear normal to her peers. Therefore, palliative surgery was pursued and currently the patient is 5Β years out from her last surgery doing well. We believe that the option of surgical palliation in this case was warranted and should be an option for similar cases in the future
Improving quality of breast cancer surgery through development of a national breast cancer surgical outcomes (BRCASO) research database
<p>Abstract</p> <p>Background</p> <p>Common measures of surgical quality are 30-day morbidity and mortality, which poorly describe breast cancer surgical quality with extremely low morbidity and mortality rates. Several national quality programs have collected additional surgical quality measures; however, program participation is voluntary and results may not be generalizable to all surgeons. We developed the Breast Cancer Surgical Outcomes (BRCASO) database to capture meaningful breast cancer surgical quality measures among a non-voluntary sample, and study variation in these measures across providers, facilities, and health plans. This paper describes our study protocol, data collection methods, and summarizes the strengths and limitations of these data.</p> <p>Methods</p> <p>We included 4524 women β₯18 years diagnosed with breast cancer between 2003-2008. All women with initial breast cancer surgery performed by a surgeon employed at the University of Vermont or three Cancer Research Network (CRN) health plans were eligible for inclusion. From the CRN institutions, we collected electronic administrative data including tumor registry information, Current Procedure Terminology codes for breast cancer surgeries, surgeons, surgical facilities, and patient demographics. We supplemented electronic data with medical record abstraction to collect additional pathology and surgery detail. All data were manually abstracted at the University of Vermont.</p> <p>Results</p> <p>The CRN institutions pre-filled 30% (22 out of 72) of elements using electronic data. The remaining elements, including detailed pathology margin status and breast and lymph node surgeries, required chart abstraction. The mean age was 61 years (range 20-98 years); 70% of women were diagnosed with invasive ductal carcinoma, 20% with ductal carcinoma in situ, and 10% with invasive lobular carcinoma.</p> <p>Conclusions</p> <p>The BRCASO database is one of the largest, multi-site research resources of meaningful breast cancer surgical quality data in the United States. Assembling data from electronic administrative databases and manual chart review balanced efficiency with high-quality, unbiased data collection. Using the BRCASO database, we will evaluate surgical quality measures including mastectomy rates, positive margin rates, and partial mastectomy re-excision rates among a diverse, non-voluntary population of patients, providers, and facilities.</p
The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast
The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1) is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to GΞ²-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase
Regulating CCTV? : We can't solve problems by using the same kind of thinking we used when we created them
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Asc1 Supports Cell-Wall Integrity Near Bud Sites by a Pkc1 Independent Mechanism
Background: The yeast ribosomal protein Asc1 is a WD-protein family member. Its mammalian ortholog, RACK1 was initially discovered as a receptor for activated protein C kinase (PKC) that functions to maintain the active conformation of PKC and to support its movement to target sites. In the budding yeast though, a connection between Asc1p and the PKC signaling pathway has never been reported. Methodology/Principal Findings: In the present study we found that asc1-deletion mutant (asc1D) presents some of the hallmarks of PKC signaling mutants. These include an increased sensitivity to staurosporine, a specific Pkc1p inhibitor, and susceptibility to cell-wall perturbing treatments such as hypotonic- and heat shock conditions and zymolase treatment. Microscopic analysis of asc1D cells revealed cell-wall invaginations near bud sites after exposure to hypotonic conditions, and the dynamic of cells β survival after this stress further supports the involvement of Asc1p in maintaining the cell-wall integrity during the mid-to late stages of bud formation. Genetic interactions between asc1 and pkc1 reveal synergistic sensitivities of a double-knock out mutant (asc1D/pkc1D) to cell-wall stress conditions, and high basal level of PKC signaling in asc1D. Furthermore, Asc1p has no effect on the cellular distribution or redistribution of Pkc1p at optimal or at cell-wall stress conditions. Conclusions/Significance: Taken together, our data support the idea that unlike its mammalian orthologs, Asc1p act
Trypanosomatid RACK1 Orthologs Show Functional Differences Associated with Translation Despite Similar Roles in Leishmania Pathogenesis
RACK1 proteins belong to the eukaryote WD40-repeat protein family and function as spatial regulators of multiple cellular events, including signaling pathways, the cell cycle and translation. For this latter role, structural and genetic studies indicate that RACK1 associates with the ribosome through two conserved positively charged amino acids in its first WD40 domain. Unlike RACK1s, including Trypanosoma brucei RACK1 (TbRACK1), only one of these two positively-charged residues is conserved in the first WD40 domain of the Leishmania major RACK1 ortholog, LACK. We compared virulence-attenuated LACK single copy (LACK/-) L. major, with L. major expressing either two LACK copies (LACK/LACK), or one copy each of LACK and TbRACK1 (LACK/TbRACK1), to evaluate the function of these structurally distinct RACK1 orthologs with respect to translation, viability at host temperatures and pathogenesis. Our results indicate that although the ribosome-binding residues are not fully conserved in LACK, both LACK and TbRACK1 co-sedimented with monosomes and polysomes in LACK/LACK and LACK/TbRACK1 L. major, respectively. LACK/LACK and LACK/TbRACK1 strains differed in their sensitivity to translation inhibitors implying that minor sequence differences between the RACK1 proteins can alter their functional properties. While biochemically distinguishable, both LACK/LACK and LACK/TbRACK1 lines were more tolerant of elevated temperatures, resistant to translation inhibitors, and displayed robust pathogenesis in vivo, contrasting to LACK/- parasites
From offender to victim-oriented monitoring : a comparative analysis of the emergence of electronic monitoring systems in Argentina and England and Wales
The increasingly psychological terrain of crime and disorder management has had a transformative impact upon
the use of electronic monitoring technologies. Surveillance technologies such as electronic monitoring βΒ EM,
biometrics, and video surveillance have flourished in commercial environments that market the benefits of
asocial technologies in managing disorderly behavior and which, despite often chimerical crime prevention
promises, appeal to the ontologically insecure social imagination. The growth of EM in criminal justice has
subsequently taken place despite, at best, equivocal evidence that it protects the public and reduces recidivism.
Innovative developments in Portugal, Argentina and the United States have re-imagined EM technologies
as more personalized devices that can support victims rather than control offenders. These developments
represent a re-conceptualization of the use of the technology beyond the neoliberal prism of rational choice
theories and offender-oriented thinking that influenced first generation thinking about EM. This paper
identifies the socio-political influences that helped conceptualize first generation thinking about EM as, firstly,
a community sentence and latterly, as a technique of urban security. The paper reviews attempts to theorize
the role and function of EM surveillance technologies within and beyond criminal justice and explores the
contribution of victimological perspectives to the use of EM 2.0
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