Publications by authors named "Aaron Mason"

Gle1 regulates gene expression at multiple steps from transcription to mRNA export to translation under stressed and non-stressed conditions. To better understand Gle1 function in stressed human cells, specific antibodies were generated that recognized the phosphorylation of threonine residue 102 (T102) in Gle1. A series of in vitro kinase assays indicated that T102 phosphorylation serves as a priming event for further phosphorylation in Gle1's N-terminal low complexity cluster.

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Multidisciplinary care in the era of COVID mitigation presented a unique opportunity to evolve a multidisciplinary Telehealth experience at the Children's Hospital Colorado. We describe our experience in developing unique programming to remain in compliance with an experience as recommended by the Parameters of Care while integrating information technology accessible via the electronic health record, multimedia adjuncts, and the integration of multiple institutional participants in creating a platform to offer care via Telehealth. Visit structure, planning, implementation, and advantages and disadvantages of the programming are discussed.

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Background: As the national opioid epidemic escalates, rates of the Hepatitis C (HCV) infection have similarly risen. Surgeons exposed intraoperatively secondary to sharp instrument or needle-sticks are affected both socioeconomically and physically. Current treatment strategies involve antiretroviral agents that have not been universally available.

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Gle1 is a conserved, essential regulator of DEAD-box RNA helicases, with critical roles defined in mRNA export, translation initiation, translation termination, and stress granule formation. Mechanisms that specify which, where, and when DDXs are targeted by Gle1 are critical to understand. In addition to roles for stress-induced phosphorylation and inositol hexakisphosphate binding in specifying Gle1 function, Gle1 oligomerizes via its N-terminal domain in a phosphorylation-dependent manner.

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A 53-year-old man presented with a number of hospital admissions for investigation of fever of unknown origin. He became gradually weaker with significant weight loss, pancytopenia and progressive splenomegaly over a 6-month period of extensive investigation. This was undertaken at different NHS hospitals with involvement of multiple medical specialists.

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Rapid expression of critical stress response factors is a key survival strategy for diseased or stressed cells. During cell stress, translation is inhibited, and a pre-existing pool of cytoplasmic mRNA-protein complexes reversibly assembles into cytoplasmic stress granules (SGs). Gle1 is a conserved modulator of RNA-dependent DEAD-box proteins required for mRNA export, translation, and stress responses.

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The mRNA lifecycle is driven through spatiotemporal changes in the protein composition of mRNA particles (mRNPs) that are triggered by RNA-dependent DEAD-box protein (Dbp) ATPases. As mRNPs exit the nuclear pore complex (NPC) in Saccharomyces cerevisiae, this remodeling occurs through activation of Dbp5 by inositol hexakisphosphate (IP )-bound Gle1. At the NPC, Gle1 also binds Nup42, but Nup42's molecular function is unclear.

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Plagiocephaly is a common condition that affects infants. It can be broadly grouped into positional and non positional plagiocephaly Positional plagiocephaly frequently resolves without intervention. Non positional plagiocephaly resulting from craniosynostosis often requires surgical intervention.

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DNA damage and other forms of replication stress can cause replication forks to stall. Replication stress response proteins stabilize and resolve stalled forks by mechanisms that include fork remodeling to facilitate repair or bypass of damaged templates. Several enzymes including SMARCAL1, HLTF, and ZRANB3 catalyze these reactions.

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HIV is now a manageable chronic condition with a near-normal life expectancy if diagnosed early. Treatment can be a simple 'one tablet, once a day' regimen with minimal side effects or interactions with other medication. Unfortunately, healthcare professionals' perception of risk of HIV infection is often incorrect and patients remain undiagnosed because healthcare professionals assume that their patients are not at risk of HIV.

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SMARCAL1, a DNA remodeling protein fundamental to genome integrity during replication, is the only gene associated with the developmental disorder Schimke immuno-osseous dysplasia (SIOD). SMARCAL1-deficient cells show collapsed replication forks, S-phase cell cycle arrest, increased chromosomal breaks, hypersensitivity to genotoxic agents, and chromosomal instability. The SMARCAL1 catalytic domain (SMARCAL1(CD)) is composed of an SNF2-type double-stranded DNA motor ATPase fused to a HARP domain of unknown function.

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SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A-like1 (SMARCAL1) is a recently identified DNA damage response protein involved in remodeling stalled replication forks. The eukaryotic single-strand DNA binding protein replication protein A (RPA) recruits SMARCAL1 to stalled forks in vivo and facilitates regression of forks containing leading strand gaps. Both activities are mediated by a direct interaction between an RPA binding motif (RBM) at the N-terminus of SMARCAL1 and the C-terminal winged-helix domain of the RPA 32 kDa subunit (RPA32C).

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Stalled replication forks are sources of genetic instability. Multiple fork-remodeling enzymes are recruited to stalled forks, but how they work to promote fork restart is poorly understood. By combining ensemble biochemical assays and single-molecule studies with magnetic tweezers, we show that SMARCAL1 branch migration and DNA-annealing activities are directed by the single-stranded DNA-binding protein RPA to selectively regress stalled replication forks caused by blockage to the leading-strand polymerase and to restore normal replication forks with a lagging-strand gap.

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Background: Medical research increasingly requires the linkage of data from different sources. Conducting a requirements analysis for a new application is an established part of software engineering, but rarely reported in the biomedical literature; and no generic approaches have been published as to how to link heterogeneous health data.

Methods: Literature review, followed by a consensus process to define how requirements for research, using, multiple data sources might be modeled.

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A new distributed model of health care management is being introduced in England. Family practitioners have new responsibilities for the management of health care budgets and commissioning of services. There are national datasets available about health care providers and the geographical areas they serve.

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SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A-like1) maintains genome integrity during DNA replication. Here we investigated its mechanism of action. We found that SMARCAL1 travels with elongating replication forks, and its absence leads to MUS81-dependent double-strand break formation.

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Streptococcus pneumoniae is an encapsulated bacterium that causes significant global morbidity and mortality. There is emerging evidence that T cells contribute to the immunity that protects humans from S. pneumoniae-associated disease.

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ATR kinase is a critical upstream regulator of the checkpoint response to various forms of DNA damage. Previous studies have shown that ATR is recruited via its binding partner ATR-interacting protein (ATRIP) to replication protein A (RPA)-covered single-stranded DNA (RPA-ssDNA) generated at sites of DNA damage where ATR is then activated by TopBP1 to phosphorylate downstream targets including the Chk1 signal transducing kinase. However, this critical feature of the human ATR-initiated DNA damage checkpoint signaling has not been demonstrated in a defined system.

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Replication protein A (RPA) is a single-stranded DNA-binding complex that is essential for DNA replication, repair, and recombination in eukaryotic cells. In addition to this canonical complex, we have recently characterized an alternative replication protein A complex (aRPA) that is unique to primates. aRPA is composed of three subunits: RPA1 and RPA3, also present in canonical RPA, and a primate-specific subunit RPA4, homologous to canonical RPA2.

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Replication protein A (RPA) is a heterotrimeric protein complex required for a large number of DNA metabolic processes, including DNA replication and repair. An alternative form of RPA (aRPA) has been described in which the RPA2 subunit (the 32-kDa subunit of RPA and product of the RPA2 gene) of canonical RPA is replaced by a homologous subunit, RPA4. The normal function of aRPA is not known; however, previous studies have shown that it does not support DNA replication in vitro or S-phase progression in vivo.

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FANCJ mutations are genetically linked to the Fanconi anemia complementation group J and predispose individuals to breast cancer. Understanding the role of FANCJ in DNA metabolism and how FANCJ dysfunction leads to tumorigenesis requires mechanistic studies of FANCJ helicase and its protein partners. In this work, we have examined the ability of FANCJ to unwind DNA molecules with specific base damage that can be mutagenic or lethal.

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Here we demonstrate a reagentless, electrochemical platform for the specific detection of proteins that bind to single- or double-stranded DNA. The sensor is composed of a double- or single-stranded, redox-tagged DNA probe which is covalently attached to an interrogating electrode. Upon protein binding the current arising from the redox tag is suppressed, indicating the presence of the target.

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Replication protein A (RPA), the eukaryotic single-stranded DNA-binding complex, is essential for multiple processes in cellular DNA metabolism. The "canonical" RPA is composed of three subunits (RPA1, RPA2, and RPA3); however, there is a human homolog to the RPA2 subunit, called RPA4, that can substitute for RPA2 in complex formation. We demonstrate that the resulting "alternative" RPA (aRPA) complex has solution and DNA binding properties indistinguishable from the canonical RPA complex; however, aRPA is unable to support DNA replication and inhibits canonical RPA function.

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