Eukaryotes have linear DNA and their telomeres are hotspots for transposons, which in some cases took over telomere maintenance. While many bacteria also have linear chromosomes and plasmids, no transposons were known to target bacterial telomeres. Here we show several families of independently evolved telomeric transposons in cyanobacteria and .
View Article and Find Full Text PDFTn3 family transposons are a widespread group of replicative transposons, notorious for contributing to the dissemination of antibiotic resistance, particularly the global prevalence of carbapenem resistance. The transposase (TnpA) of these elements catalyzes DNA breakage and rejoining reactions required for transposition. However, the molecular mechanism for target site selection with these elements remains unclear.
View Article and Find Full Text PDFMitochondria, central organelles pivotal for eukaryotic cell function, extend their influence beyond ATP production, encompassing roles in apoptosis, calcium signaling, and biosynthesis. Recent studies spotlight two emerging determinants of mitochondrial functionality: intramitochondrial viscosity and sulfur dioxide (SO) levels. While optimal mitochondrial viscosity governs molecular diffusion and vital processes like oxidative phosphorylation, aberrations are linked with neurodegenerative conditions, diabetes, and cancer.
View Article and Find Full Text PDFDisabil Rehabil Assist Technol
July 2024
Wheelchair users (WCUs) face additional challenges than non-WCU to multi-tasking (i.e. open doors, cook, use a cell-phone) while navigating their environments.
View Article and Find Full Text PDFThe Tn7 family of transposons is notable for its highly regulated integration mechanisms, including programmable RNA-guided transposition. The targeting pathways rely on dedicated target selection proteins from the TniQ family and the AAA+ adaptor TnsC to recruit and activate the transposase at specific target sites. Here, we report the cryoelectron microscopy (cryo-EM) structures of TnsC bound to the TniQ domain of TnsD from prototypical Tn7 and unveil key regulatory steps stemming from unique behaviors of ATP- versus ADP-bound TnsC.
View Article and Find Full Text PDFDisabil Rehabil Assist Technol
November 2024
Objective: There is growing evidence that fear of falling (FOF) is common in people who use wheelchairs full-time and negatively influence their performance of daily activities and quality of life. The purpose of this study was to gain an in-depth understanding of perceptions related to FOF among people who use wheelchairs full-time.
Methods: Mixed-method analysis was conducted using semi-structured interviews and surveys to gain insight into FOF.
CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated nuclease) defense systems have been naturally coopted for guide RNA-directed transposition on multiple occasions. In all cases, cooption occurred with diverse elements related to the bacterial transposon Tn7. Tn7 tightly controls transposition; the transposase is activated only when special targets are recognized by dedicated target-site selection proteins.
View Article and Find Full Text PDFThis review investigated the ability of dual-task tests to predict falls in people with neurological disorders. Databases were searched to identify prospective cohort studies that analyzed dual-task testing and falls in people with neurological disorders. Reviewers screened studies for eligibility and extracted key information like participant characteristics, intervention details, outcome measures, and significant outcomes.
View Article and Find Full Text PDFBackground: Fear of falling (FOF) is a common concern among persons with multiple sclerosis (MS) and affects the performance of their daily living activities. Falls may result in FOF, leading to worsening of symptoms of MS, physical deconditioning, and exposure to future falls. This may trigger a vicious cycle between FOF and falls.
View Article and Find Full Text PDFMobile genetic elements play an important role in the acquisition of antibiotic and biocide resistance, especially through the formation of resistance islands in bacterial chromosomes. We analyzed the contribution of Tn7-like transposons to island formation and diversification in the nosocomial pathogen Acinetobacter baumannii and identified four separate families that recognize different integration sites. One integration site is within the comM gene and coincides with the previously described Tn6022 elements suggested to account for the AbaR resistance island.
View Article and Find Full Text PDFObjectives: To compare acute cardiorespiratory responses during high intensity interval training (HIIT) and moderate intensity continuous training (MICT) on a recumbent handcycle in persons with spinal cord injury (PwSCI).
Methods: Eleven males and nine females with chronic SCI (T3 - L5), aged 23 (9) years, participated in this within-subject design. Based off peak power outputs from an incremental test to exhaustion, participants engaged in a HIIT and MICT session at matched workloads on a recumbent handcycle.
Wheelchair users (WCUs) face high rates of shoulder overuse injuries. As exercise is recommended to reduce cardiovascular disease prevalent among WCUs, it is becoming increasingly important to understand the mechanisms behind shoulder soft-tissue injury in WCUs. Understanding the kinetics and kinematics during upper-limb propulsion is the first step toward evaluating soft-tissue injury risk in WCUs.
View Article and Find Full Text PDFThis mixed-method project investigated how people with spinal cord injury perceive high-intensity interval training (HIIT). Using a recumbent hand cycle, 11 active men and 9 active women with spinal cord injury or related disease participated in a single HIIT and moderate-intensity continuous training (MICT) session. Following exercise, participants completed surveys assessing enjoyment, self-efficacy, and outcome expectations.
View Article and Find Full Text PDFPeople with spinal cord injuries (PwSCI) are at high risk of developing cardiovascular disease (CVD). While regular exercise can reduce risk of CVD, PwSCI face various barriers to exercise, including high rates of upper limb injuries, especially in the shoulder. Handcycling high intensity interval training (HIIT), which consists of periods of high intensity exercise followed by rest, is a potential exercise solution, but the musculoskeletal safety of HIIT is still unknown.
View Article and Find Full Text PDFCRISPR-cas loci typically contain CRISPR arrays with unique spacers separating direct repeats. Spacers along with portions of adjacent repeats are transcribed and processed into CRISPR(cr) RNAs that target complementary sequences (protospacers) in mobile genetic elements, resulting in cleavage of the target DNA or RNA. Additional, standalone repeats in some CRISPR-cas loci produce distinct cr-like RNAs implicated in regulatory or other functions.
View Article and Find Full Text PDFCRISPR-associated transposons (CASTs) are natural RNA-directed transposition systems. We demonstrate that transposon protein TniQ plays a central role in promoting R-loop formation by RNA-guided DNA-targeting modules. TniQ residues, proximal to CRISPR RNA (crRNA), are required for recognizing different crRNA categories, revealing an unappreciated role of TniQ to direct transposition into different classes of crRNA targets.
View Article and Find Full Text PDFCRISPR- loci typically contain CRISPR arrays with unique spacers separating direct repeats. Spacers along with portions of adjacent repeats are transcribed and processed into CRISPR(cr) RNAs that target complementary sequences (protospacers) in mobile genetic elements, resulting in cleavage of the target DNA or RNA. Additional, standalone repeats in some CRISPR- loci produce distinct cr-like RNAs implicated in regulatory or other functions.
View Article and Find Full Text PDFBackground: Non-level transfers are some of the most demanding tasks for manual wheelchair users. Safely performing these transfer tasks may be needed for maintaining long-term upper limb health. This cross-sectional study aimed to examine the influence of gender on the head-hip technique and lead arm kinematics during multi-height transfers in manual wheelchair users.
View Article and Find Full Text PDFCRISPR-Cas defense systems have been naturally coopted for guide RNA-directed transposition by Tn7 family bacterial transposons. We find cyanobacterial genomes are rich in Tn7-like elements, including most of the known guide RNA-directed transposons, the type V-K, I-B1, and I-B2 CRISPR-Cas based systems. We discovered and characterized an example of a type I-D CRISPR-Cas system which was naturally coopted for guide RNA-directed transposition.
View Article and Find Full Text PDFNeurorehabil Neural Repair
December 2022
Background: Mobility and cognitive impairments are often associated with increased fall risk among people with multiple sclerosis (PwMS). However, evidence on the concurrent assessment of gait or balance and cognitive tasks (dual-task) to predict falls appears to be inconsistent.
Objective: To summarize the ability of gait or balance dual-task testing to predict future falls among PwMS.
CRISPR-associated transposons (CASTs) are Tn7-like elements that are capable of RNA-guided DNA integration. Although structural data are known for nearly all core transposition components, the transposase component, TnsB, remains uncharacterized. Using cryo-electron microscopy (cryo-EM) structure determination, we reveal the conformation of TnsB during transposon integration for the type V-K CAST system from (ShCAST).
View Article and Find Full Text PDFBrains of 42 COVID-19 decedents and 107 non-COVID-19 controls were studied. RT-PCR screening of 16 regions from 20 COVID-19 autopsies found SARS-CoV-2 E gene viral sequences in 7 regions (2.5% of 320 samples), concentrated in 4/20 subjects (20%).
View Article and Find Full Text PDFTn7 is a bacterial transposon with relatives containing element-encoded CRISPR-Cas systems mediating RNA-guided transposon insertion. Here, we present the 2.7 Å cryoelectron microscopy structure of prototypic Tn7 transposase TnsB interacting with the transposon end DNA.
View Article and Find Full Text PDFDisabil Rehabil Assist Technol
January 2024
Purpose: Gait and balance impairments are associated with falls and reduced quality of life among survivors of stroke (SS). Effective methods to assess these impairments at-home and in-clinic can help reduce fall risks and improve functional outcomes. Smartphone technology may be able to evaluate these impairments.
View Article and Find Full Text PDFTn7 transposable elements are unique for their highly specific, and sometimes programmable, target-site selection mechanisms and precise insertions. All the elements in the Tn7 family utilize an AAA+ adaptor (TnsC) to coordinate target-site selection with transpososome assembly and to prevent insertions at sites already containing a Tn7 element. Owing to its multiple functions, TnsC is considered the linchpin in the Tn7 element.
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