Investigating the role of WDR81 in progressive neurological dysfunction

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A complete understanding of the physiology underlying progressive forms of neurological dysfunction is a key challenge to society. This PhD project aims to understand the role of the WD40-BEACH domain containing neuronal protein WDR81 in these conditions. We have performed a forward genetic suppressor screen to identify novel gene mutations that bypass the requirement of an essential protein in neurotransmitter release. From this screen, we identified that novel mutations in WDR81 could bypass this essential protein and restore wild-type levels of exocytosis. Although WDR81 function has been largely uninvestigated, specific mutations in the protein have been linked with severe pathophysiological defects in humans cerebellar ataxia, cerebro-cerebellar hypoplasia, mental retardation and quadrupedal locomotion (1). In agreement with these symptoms, mice with WDR81 mutations display tremors, abnormal gait as well as progressive neurodegeneration. The mechanism for WDR81 function in these conditions is currently unknown although accumulating evidence points towards a role for WDR81 in intracellular trafficking and autophagy (2). This studentship will allow us to pinpoint the exact function of this novel protein in membrane fusion and determine mechanistically how mutations in WDR81 underlie complex neurological defects in humans. The student undertaking this project will receive multidisciplinary training in a broad combination of genetic, cellular and molecular approaches as well as in vitro biochemical techniques and electrophysiological recordings. A targeted genetic approach will be undertaken in the Barclay lab at the University of Liverpool using Cas9-CRISPR gene editing. The gene edited strains will be analysed for progressive deterioration in neurological function using functional assays for chemosensory and motor neuron output as the animal ages. In conjunction with these experiments, biochemical approaches will be adopted to identify binding partners for WDR81 using proximity-dependent biotin labelling. Finally the student will continue the work in the Seward lab at the University of Sheffield to determine the molecular mechanism of WDR81 function on exocytosis using patch clamp electrophysiology, electrochemical and TIRF (total internal reflection fluorescence) techniques to quantify vesicle docking and fusion at a precise level. From this project, the student will become familiar with modern genetic, biochemical and functional assays to study neurological function during ageing. The ultimate aim of these studies will be to identify novel insights into the role of WDR81 in determining progressive neurological dysfunction. We will provide training in a wide array of modern genetic, biochemical and physiological techniques and deliver novel insights into the role of a unique protein in determining progressive neurological dysfunction.