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Drake, M.

Publications and source records attributed to Drake, M..

5 recordsLinked to original sources

Astrocytes transform the transcriptomic and epigenetic landscape of developing cortical neurons to promote activity via intrinsic excitability control

Astrocytes are implicated in neuronal development and function, particularly of synapses, but their genome-wide impact is unclear. We show that cortical astrocytes trigger epigenetic remodelling in developing cortical neurons and widespread transcriptomic changes distinct from neurons intrinsic developmental trajectory. These changes can cause an emergence of neuronal firing activity independent of functional excitatory synaptogenesis. The mechanism is via through astrocyte-derived signals causing the transcriptional repression of inwardly-rectifying K+-channels (Kirs), causing a pro-excitatory shift in intrinsic properties. This places neurons in a zone of excitability whereupon cell-autonomous homeostatic control was activated, also associated with Kir regulation. Astrocyte-induced neuronal genes were enriched for schizophrenia, epilepsy, ADHD and Alzheimers disease risk, disorders associated with circuit imbalance. Thus, astrocyte-to-neuron signaling can alter firing via intrinsic properties in addition to the classical synaptogenic mechanism. The opposing actions of astrocytes and neuronal activity in regulating neuronal intrinsic properties may prevent hyper- or hypo-activity in neuronal circuits

neuroscience↗

Toward a model of uORF-mediated translational control: An integrated bioinformatic and experimental approach

Upstream open reading frames (uORFs) are short translated regions that occur in the 5{square} untranslated regions (5{square} UTRs) of mRNA transcripts where they primarily serve to repress expression translation of the downstream primary open reading frame (pORF). Their widespread presence across mammalian transcriptomes suggests an important role in shaping the proteome, although the mechanistic basis of their regulatory effects remain incompletely understood. Here we present an integrated experimental and computational investigation into the features that govern uORF-mediated translation control. Using high-resolution proteomics data from 29 healthy human tissues and machine learning-based simulations, we have systematically dissected how features including uORF length, amino acid composition, start codon position, stop codon position, and Kozak context influence repressive activity, and performed experimental validation using reporter gene constructs. We also investigated how multiple uORFs within a single 5{square} UTR can interact in synergistic or antagonistic ways, with the potential to produce counterintuitive effects on pORF translation. From these studies, we present a model of uORF function, suggesting a hierarchy of uORF feature importance, and proposing that a combination of uORF translation initiation probability, ribosome recycling rate, intercistronic ternary complex recharging requirements, and ribosome stalling mechanisms underlie uORF repressive activity. Together, these studies provide a comprehensive view of the molecular logic underlying uORF activity, offering new insights into their endogenous and highlighting their potential as targets for drug development.

biochemistry↗

RWRtoolkit: multi-omic network analysis using random walks on multiplex networks in any species

Leveraging the use of multiplex multi-omic networks, key insights into genetic and epigenetic mechanisms supporting biofuel production have been uncovered. Here, we introduce RWRtoolkit, a multiplex generation, exploration, and statistical package built for R and command line users. RWRtoolkit enables the efficient exploration of large and highly complex biological networks generated from custom experimental data and/or from publicly available datasets, and is species agnostic. A range of functions can be used to find topological distances between biological entities, determine relationships within sets of interest, search for topological context around sets of interest, and statistically evaluate the strength of relationships within and between sets. The command-line interface is designed for parallelisation on high performance cluster systems, which enables high throughput analysis such as permutation testing. Several tools in the package have also been made available for use in reproducible workflows via the KBase web application.

bioinformatics↗

The RPA complex orchestrates K63-linked deubiquitination via ZUP1

Ubiquitin signaling is regulated by deubiquitinating enzymes (DUBs), which can edit or remove ubiquitin from substrates. Recently, ZUP1 was discovered as the founding and only member of a novel DUB class that cleaves long K63-linked ubiquitin chains, with a putative role in DNA repair. However, ZUP1 has poor activity on its own, suggesting additional mechanisms exist to promote its activity in cells. Here, using a range of cellular, biochemical, and structural proteomics approaches, we show that ZUP1 directly interacts with the RPA complex, a single-stranded DNA binding protein complex involved in DNA replication and multiple DNA repair processes. Functionally, the ZUP1-RPA complex interaction dramatically stimulates ZUP1 K63-linked DUB activity, which occurs through S1 and S1 site communication. Collectively, our results suggest a mechanism that couples sensing of ssDNA to the activation of K63-linked deubiquitination via the ZUP1-RPA complex.

biochemistry↗

Collateral damage: Identification and characterisation of spontaneous mutations causing deafness from a targeted knockout programme

Mice carrying targeted mutations are important for investigating gene function and the role of genes in disease, but the process of culturing embryonic stem cells during the making of a targeted allele offers opportunities for spontaneous mutations to arise. Identifying spontaneous mutations relies on the detection of phenotypes segregating independently of targeted alleles, and many phenotypes are easy to miss if not specifically looked for. Here we present data from a large, targeted knockout programme in which mice were analysed through a phenotyping pipeline. Twenty-five lines out of 1311 displayed different deafness phenotypes that did not segregate with the targeted allele. We have identified 8 different mutations causing deafness in 16 of these 25 lines and characterised the resulting phenotypes. Our data show that spontaneous mutations with observable effects on phenotype are a common side effect of intensive breeding programmes, including those underlying targeted mutation programmes.

genetics↗