Biology subjects

Roe, S. M.

Publications and source records attributed to Roe, S. M..

5 recordsLinked to original sources

bioRxiv2026

Structure-function studies of HRIKD-{triangleup}KI, a Minimal Kinase Domain of Human Heme-Regulated Inhibitor Kinase

EIF2 kinase heme-regulated inhibitor (HRI) is a novel target for haematological malignancies with modulators reported to trigger cell death via the HRI-eIF2-ATF4 pathway. We report a protocol for producing the minimal kinase domain of full-length human HRI, termed HRIKD-{Delta}KI, where the unstructured 140 amino acid (aa) kinase insert (KI) within HRI kinase domain (HRIKD) is replaced with a 2aa glycine/serine (GS) linker. X-ray crystal structures were determined of apo-HRIKD-{Delta}KI and of its complex with ATP at 2.1 & 2.5 [A] resolution respectively. Both structures display a canonical bi-lobal kinase fold. However, they remain in a non-productive state with a displaced C-helix, disassembled R-spine, and a disordered activation segment hindering the substrate site. Biophysical assays (fluorescence based thermal shift & Synchrotron Radiation Circular Dichroism) demonstrate HRIKD-{Delta}KI retains its functional ligand-binding conformation. All together, these findings define structural and ligand-binding features of HRI to support ongoing drug discovery efforts in blood cancer.

biochemistry↗

bioRxiv2025

CCDC103-mediated assembly of the R2C complex links RUVBL1-RUVBL2 to Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a genetic disorder caused by defective cilia motility, powered by axonemal dynein motors. Assembly of these motors is facilitated by the molecular chaperone HSP90, its co-chaperone RUVBL1-RUVBL2 and adaptor proteins such as CCDC103 (aka DNAAF19). Mutations in CCDC103 identified in PCD patients impair dynein assembly, contributing to the disease pathology. Here, we present the cryo-electron microscopy structure of the human RUVBL1-RUVBL2-CCDC103 complex at 3.2[A] resolution, a chaperone assembly we refer to as R2C. It comprises a hetero-hexameric RUVBL1-RUVBL2 ring bound to three CCDC103 molecules via their RUVBL2-binding domains (RBDs), which have additional functions. Unlike RPAP3 of R2TP, a previously defined co-chaperone of HSP90, CCDC103 lacks a PIH1D1-binding motif and TPR domains, but its flexible N-terminal region regulates RUVBL1-RUVBL2 oligomerisation. Our characterisation of the R2C complex presented here enhances understanding of the intricate protein network involved in Hsp90-mediated assembly of dynein motors and how adaptor mutations contribute to PCD.

biochemistry↗

bioRxiv2023

The Crystal Structure of the Hsp90-LA1011 Complex and the Mechanism by which LA1011 may Improve the Prognosis of Alzheimer's Disease.

Chaperone systems play a major role in the decline of cognition and contribute to neurological pathologies such as Alzheimers disease (AD). While such a decline may occur naturally with age or with stress or trauma, the mechanisms involved have remained elusive. The current models suggest that amyloid-{beta} (A{beta}) plaque formation leads to the hyperphosphorylation of tau by a Hsp90 dependent process that triggers tau neurofibrillary tangle formation and neurotoxicity. Several co-chaperones of Hsp90 can influence the phosphorylation of tau, including FKBP51, FKBP52 and PP5. In particular elevated levels of FKBP51 occur with age and stress and are further elevated in AD. Recently, the dihydropyridine, LA1011 was shown to reduce tau pathology and amyloid plaque formation in transgenic AD mice, probably through its interaction with Hsp90 although the precise mode of action is currently unknown. Here, we present a co-crystal structure of LA1011 in complex with a fragment of Hsp90. We show that LA1011 can disrupt binding of FKBP51, which might help to rebalance the Hsp90-FKBP51 chaperone machinery and provide a favourable prognosis towards AD. Clinically, this is highly significant, as AD is generally a disease affecting older patients, where slowing of disease progression could result in AD no longer being life limiting.

molecular biology↗

bioRxiv2021

Tyrosine 121 moves revealing a druggable pocket that couples catalysis to ATP-binding in serine racemase

Human serine racemase (hSR) catalyses racemisation of L-serine to D-serine, the latter of which is a co-agonist of the NMDA subtype of glutamate receptors that are important in synaptic plasticity, learning and memory. In a closed hSR structure containing the allosteric activator ATP, the inhibitor malonate is enclosed between the large and small domains while ATP is distal to the active site, residing at the dimer interface with the Tyr121 hydroxyl group contacting the ATP a-phosphate. In contrast, in open hSR structures, Tyr121 sits in the core of the small domain with its hydroxyl contacting the key catalytic residue Ser84. The ability to regulate SR activity by flipping Tyr121 from the core of the small domain to the dimer interface appears to have evolved in animals with a CNS. Multiple X-ray crystallographic enzymefragment structures show that Tyr121 is flipped out of its pocket, suggesting that this pocket is druggable.

biophysics↗

bioRxiv2020

Uncovering an allosteric mode of action for a selective inhibitor of human Bloom syndrome protein

BLM (Bloom syndrome protein) is a RECQ-family helicase involved in the dissolution of complex DNA structures and repair intermediates. Synthetic lethality analysis implicates BLM as a promising target in a range of cancers with defects in the DNA damage response, however selective small molecule inhibitors of defined mechanism are currently lacking. Here we identify and characterise a specific inhibitor of BLMs ATPase-coupled DNA helicase activity, by allosteric trapping of a DNA-bound translocation intermediate. Crystallographic structures of BLM-DNA-ADP-inhibitor complexes identify a hitherto unknown interdomain interface, whose opening and closing are integral to translocation of ssDNA, and which provides a highly selective pocket for drug discovery. Comparison with structures of other RECQ helicases provides a model for branch migration of Holliday junctions by BLM.

biochemistry↗