Biology subjects

Surridge, K. J.

Publications and source records attributed to Surridge, K. J..

6 recordsLinked to original sources

bioRxiv2026

Conformation governs cellular behaviors of LRRK2 Parkinson's disease variants

Gain-of-function of leucine-rich repeat kinase 2 (LRRK2) is a common cause of Parkinson's disease (PD). In its autoinhibited state, the leucine-rich repeats of LRRK2 block the kinase active site, preventing substrate phosphorylation. Displacing the repeats ('unlatching') primes LRRK2 for activity. Preferential unlatching causes increased substrate phosphorylation of the PD allele LRRK2[R1441H], but not LRRK2[G2019S]. Here, we define a large class of PD-associated 'unlatching' mutations based on their effect on LRRK2 conformation. Unlatching mutants show increased localization to membranes, the site of LRRK2's Rab substrates. Unlatching mutants are also characterized by decreased LRRK2 S935 phosphorylation, which we define as a biomarker of conformation. This framework resolves the mechanism of variants such as I2020T, which structural studies could not predict. Overall, we establish unlatching as a unifying mechanism for most PD-linked variants and describe measurable readouts for identifying LRRK2-driven disease.

cell biology↗

bioRxiv2026

The structural basis for LRRK2's activation and autoinhibition

Mutations in Leucine-Rich Repeat Kinase 2 (LRRK2) are the second most common cause of autosomal-dominant Parkinsons disease (PD), and increased LRRK2 kinase activity is also observed in idiopathic PD, making LRRK2 a major actionable therapeutic target. LRRK2 is a 286-kDa multidomain enzyme containing a Ras-like GTPase (ROC) and a kinase domain. Using cryo-EM, biochemical reconstitution, and cell-based assays, we show that the ROC GTPase governs switching between autoinhibited and active states: GTP binding promotes activation, whereas GDP binding enforces autoinhibition. Two common PD-linked mutations, G2019S and R1441C/G/H, activate LRRK2 through distinct structural mechanisms, revealing genotype-specific routes to dysregulation. These findings provide a unified framework for understanding LRRK2 regulation with broad therapeutic implications. Stabilizing the GDP-bound state may inhibit LRRK2 by maintaining autoinhibition, whereas promoting the GTP-bound state could be advantageous in specific cellular contexts, such as the lung, where increased LRRK2 kinase activity may play protective or regulatory roles.

neuroscience↗

bioRxiv2025

Proteome-wide impact of LRRK1 and 2 inhibitors on protein interactions and phosphorylation

The Leucine-rich repeat kinases 1 and 2 (LRRK1 and 2) are large, multidomain proteins and closely related members of the Roco protein family. They share a high similarity in domain structure and are both phosphorylate members of the Rab GTPase family. However, despite these similarities, there are substantial differences between the two kinases. While mutations to LRRK1 are only implicated in rare cases of osteopetrosis, LRRK2 is associated with multiple diseases, most prominently with familial and sporadic forms of Parkinsons disease, where pathogenic LRRK2 is associated with an increased kinase activity. While LRRK2 has received major attention from the research community, LRRK1 has been largely understudied. In this work, we employ proximity labelling mass spectrometry in combination with quantitative phosphoproteomics in a model cell line to obtain the cellular interactomes of LRRK1 and LRRK2 and corresponding phosphorylation sites. We then use this dataset to characterize the impact of small molecules targeting both LRRK1 and 2. We identify phosphorylation sites across the proteome that are impacted by these inhibitors and identify novel candidate substrates for LRRK2, including MICALL2. Taken together our data provide a powerful resource for future studies on the cellular role and function of LRRK proteins and their potential use as therapeutic targets.

molecular biology↗

bioRxiv2024

Type-II kinase inhibitors that target Parkinson's Disease-associated LRRK2

Aberrant increases in kinase activity of leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinsons disease (PD). Numerous LRRK2-selective type-I kinase inhibitors have been developed and some have entered clinical trials. In this study, we present the first LRRK2-selective type-II kinase inhibitors. Targeting the inactive conformation of LRRK2 is functionally distinct from targeting the active-like conformation using type-I inhibitors. We designed these inhibitors using a combinatorial chemistry approach fusing selective LRRK2 type-I and promiscuous type-II inhibitors by iterative cycles of synthesis supported by structural biology and activity testing. Our current lead structures are selective and potent LRRK2 inhibitors. Through cellular assays, cryo-electron microscopy structural analysis, and in vitro motility assays, we show that our inhibitors stabilize the open, inactive kinase conformation. These new conformation-specific compounds will be invaluable as tools to study LRRK2s function and regulation, and expand the potential therapeutic options for PD.

cell biology↗

bioRxiv2022

Molecular architecture of the autoinhibited kinesin-1 lambda particle

Despite continuing progress in kinesin enzyme mechanochemistry and emerging understanding of the cargo recognition machinery, it is not known how these functions are coupled and controlled by the alpha-helical coiled coils encoded by a large component of kinesin protein sequences. Here, we combine computational structure prediction with single-particle negative stain electron microscopy to reveal the coiled-coil architecture of heterotetrameric kinesin-1, in its compact state. An unusual flexion in the scaffold enables folding of the complex, bringing the kinesin heavy chain-light chain interface into close apposition with a tetrameric assembly formed from the region of the molecule previously assumed to be the folding hinge. This framework for autoinhibition is required to uncover how engagement of cargo and other regulatory factors drive kinesin-1 activation. Summary statementIntegration of computational structure prediction with electron microscopy reveals the coiled-coil architecture of the autoinhibited compact conformer of the microtubule motor, kinesin-1.

cell biology↗

bioRxiv2019

In situ cryo-electron tomography reveals filamentous actin within the microtubule lumen

Microtubules and filamentous (F-) actin engage in complex interactions to drive many cellular processes from subcellular organisation to cell division and migration. This is thought to be largely controlled by proteins that interface between the two structurally distinct cytoskeletal components. Here, we use cryo-electron tomography to demonstrate that the microtubule lumen can be occupied by extended segments of F-actin in small-molecule induced, microtubule-based cellular projections. We uncover an unexpected versatility in cytoskeletal form that may prompt a significant development of our current models of cellular architecture and offer a new experimental approach for the in-situ study of microtubule structure and contents.

cell biology↗