35 research outputs found
Choosing best practices for managing impacts of trawl fishing on seabed habitats and biota
Bottom trawling accounts for almost one quarter of global fish landings but may also have significant and unwanted impacts on seabed habitats and biota. Management measures and voluntary industry actions can reduce these impacts, helping to meet sustainability objectives for fisheries, conservation and environmental management. These include changes in gear design and operation of trawls, spatial controls, impact quotas and effort controls. We review nine different measures and actions and use published studies anda simple conceptual model to evaluate and compare their performance. The risks and benefits of these management measures depend on the extent to which the fishery is already achieving management objectives for target stocks and the characteristics of the management system that is already in place. We offer guidance on identifying best practices for trawl-fisheries management and show that best practices and their likelihood of reducing trawling impacts depend on local, national and regional management objectives and priorities, societal values and resources for implementation. There is no universalbest practice, and multiple management measures and industry actions are required to meet sustainability objectives and improve trade-offs between food production and environmental protection
Chemical Control of a CRISPR-Cas9 Acetyltransferase
Lysine acetyltransferases (KATs)
play a critical role in the regulation
of transcription and other genomic functions. However, a persistent
challenge is the development of assays capable of defining KAT activity
directly in living cells. Toward this goal, here we report the application
of a previously reported dCas9-p300 fusion as a transcriptional reporter
of KAT activity. First, we benchmark the activity of dCas9-p300 relative
to other dCas9-based transcriptional activators and demonstrate its
compatibility with second generation short guide RNA architectures.
Next, we repurpose this technology to rapidly identify small molecule
inhibitors of acetylation-dependent gene expression. These studies
validate a recently reported p300 inhibitor chemotype and reveal a
role for p300s bromodomain in dCas9-p300-mediated transcriptional
activation. Comparison with other CRISPR-Cas9 transcriptional activators
highlights the inherent ligand tunable nature of dCas9-p300 fusions,
suggesting new opportunities for orthogonal gene expression control.
Overall, our studies highlight dCas9-p300 as a powerful tool for studying
gene expression mechanisms in which acetylation plays a causal role
and provide a foundation for future applications requiring spatiotemporal
control over acetylation at specific genomic loci
Chemical Control of a CRISPR-Cas9 Acetyltransferase
Lysine acetyltransferases (KATs)
play a critical role in the regulation
of transcription and other genomic functions. However, a persistent
challenge is the development of assays capable of defining KAT activity
directly in living cells. Toward this goal, here we report the application
of a previously reported dCas9-p300 fusion as a transcriptional reporter
of KAT activity. First, we benchmark the activity of dCas9-p300 relative
to other dCas9-based transcriptional activators and demonstrate its
compatibility with second generation short guide RNA architectures.
Next, we repurpose this technology to rapidly identify small molecule
inhibitors of acetylation-dependent gene expression. These studies
validate a recently reported p300 inhibitor chemotype and reveal a
role for p300s bromodomain in dCas9-p300-mediated transcriptional
activation. Comparison with other CRISPR-Cas9 transcriptional activators
highlights the inherent ligand tunable nature of dCas9-p300 fusions,
suggesting new opportunities for orthogonal gene expression control.
Overall, our studies highlight dCas9-p300 as a powerful tool for studying
gene expression mechanisms in which acetylation plays a causal role
and provide a foundation for future applications requiring spatiotemporal
control over acetylation at specific genomic loci
Characterizing the Covalent Targets of a Small Molecule Inhibitor of the Lysine Acetyltransferase P300
C646
inhibits the lysine acetyltransferases (KATs) p300 and CBP
and represents the most potent and selective small molecule KAT inhibitor
identified to date. To gain insights into the cellular activity of
this epigenetic probe, we applied chemoproteomics to identify covalent
targets of the C646 chemotype. Modeling and synthetic derivatization
was used to develop a clickable analogue (C646-yne) that inhibits
p300 similarly to the parent compound and enables enrichment of bound
proteins. LCâMS/MS identified the major covalent targets of
C646-yne as highly abundant cysteine-containing proteins, and follow-up
studies found that C646 can inhibit tubulin polymerization in vitro.
Finally, we provide evidence that thiol reactivity of C646 may limit
its ability to antagonize acetylation in cells. These findings should
enable a more precise interpretation of studies utilizing C646 as
a chemical probe of KAT activity and suggest that an underappreciated
liability of electrophile-containing inhibitors is a reduction in
their cellular potency due to consumption by abundant protein and
metabolite thiol sinks