Biology subjects

Twelvetrees, A. E.

Publications and source records attributed to Twelvetrees, A. E..

3 recordsLinked to original sources

bioRxiv2026

A universal protein ladder for standardisation of diverse FRET assays

Fluorescence resonance energy transfer (FRET) is the highly distance dependent (3-10 nm) transfer of energy from a donor to an acceptor fluorophore, with transfer efficiency inversely proportional to the distance between the fluorophores. Consequently FRET serves as a powerful spectroscopic ruler for probing molecular interactions. Whilst cell based FRET assays report bulk relative changes in FRET efficiency in a population, single molecule FRET (smFRET) is capable of deconvoluting these population averages into distinct structural states. However, the lack of universal benchmarks prevents the direct translation of in vitro distance measurements to the intracellular environment and vice versa. Here, we present a modular protein ladder designed to harmonize FRET data across diverse platforms. Using an engineered repeating TPR motif and self-labeling enzymes, we demonstrate that our standards yield consistent FRET efficiencies across expression systems (mammalian and bacterial) and labelling strategies (self labelling enzymes and click chemistry with non-canonical amino acids). By providing a predictable calibration curve, the ladder enables interpolation between different experimental FRET modalities, including confocal smFRET, flow cytometry based-FRET and Fluorescence Lifetime Imaging Microscopy FRET (FLIM-FRET). This is the necessary infrastructure to relate molecular distances from the test tube to the cell.

biophysics↗

bioRxiv2024

Kinesin-1 is highly flexible and adopts an open conformation in the absence of cargo

Kinesin-1 is an essential anterograde microtubule motor protein. The core kinesin motor is a homodimer of two heavy chains; N-terminal motor domains hydrolyse ATP and walk along microtubules, whilst a long elongated coiled-coil stalk and an intrinsically disordered C-terminal tail region bind cargos. Kinesin autoinhibition is key to preventing futile ATP consumption and occurs, at least in part, through direct interactions between N-terminal motor domains and C-terminal inhibitory motifs. Despite significant advances in our understanding of kinesin walking, little is known about the kinesin-1 conformational landscape of the stalk and tail domains. Here we apply solution based biophysical analysis tools to study conformational changes in kinesin-1, with full rotational freedom, and in response to changes in ionic strength, mutations, and the presence of microtubules. This has allowed us to uncover the inherent flexibility in kinesin-1 which gives insights into autoinhibition and the regulation of intracellular transport.

biophysics↗

bioRxiv2024

Cooperation between Intrinsically Disordered Regions regulates CBP condensate behaviour.

Intrinsically disordered regions (IDRs) have emerged as crucial regulators of protein function, allowing proteins to sense and respond to their environment. Creb binding protein (CBP) and EP300 (p300) are transcription coactivators that regulate gene expression in multicellular organisms, following their recruitment to cis-regulatory elements. CBP and p300 contain large IDRs, however little is known about how these different IDRs work together to regulate CBP function. Here, we show that CBP-IDRs cooperate to control different aspects of CBP behaviour in the nucleus, by regulating the properties of fluid-like condensates formed by endogenous CBP. We show how IDRs with different sequence properties make unique contributions to CBP behaviour by establishing a balance between positive and negative regulation of CBP condensates. These conflicting interactions are functionally important, shaping CBPs response to factors such as lysine acetylation, that influence condensate formation. When disrupted, regulatory CBP-IDRs change how CBP interacts with chromatin, alter patterns of CBP-dependent histone acetylation and change gene expression. Together, our work highlights how IDRs with different sequences, spatially segregated in the same protein, can cooperate to shape protein function.

molecular biology↗