Search bioRxiv⌕ Search

Biology subjects

DeFoor, N.

Publications and source records attributed to DeFoor, N..

2 recordsLinked to original sources

Impaired Complex I dysregulates neural/glial precursors and corpus callosum development revealing postnatal defects in Leigh Syndrome mice

Leigh syndrome (LS) is a complex, genetic mitochondrial disorder defined by neurodegenerative phenotypes with pediatric manifestation. However, recent clinical studies report behavioral phenotypes in human LS patients that are more reminiscent of neurodevelopmental delays. To determine if disruptions in epochs of rapid brain growth during infancy precede the hallmark brain lesions that arise during childhood, we evaluated neural and glial precursor cellular dynamics in a mouse model of LS. Single cell RNA sequencing along with histological and anatomical assessments were performed in NDUFS4 KO mice and compared with controls to determine the impact of Complex I deficiency on neural stem cells, their neuronal and oligodendroglial progeny, lineage progression, and overt differences in specific brain regions. Our findings show disruptions in all categories, specifically within the subventricular zone and corpus callosum. Given that LS is purely considered a neurodegenerative disease, we propose that mitochondrial dysfunction is a neurodevelopmental signature predating classic diagnosis in LS.

neuroscience↗

NAK associated protein 1 is required to activate Tank binding kinase 1 to regulate mitosis

Subcellular location and activation of Tank Binding Kinase 1 (TBK1) govern precise progression through mitosis. Either loss of activated TBK1 or its sequestration from the centrosomes causes error in mitosis and growth defects. Yet, what regulates its recruitment and activation on the centrosomes is unknown. We identified that NAK Associated Protein 1 (NAP1) is essential for mitosis which binds to TBK1 on the centrosomes to activate it. Loss of NAP1 causes several mitotic and cytokinetic defects due to inactivation of TBK1. Our quantitative phosphoproteomics identified numerous TBK1 substrates that are not only confined to the centrosomes but also are associated with microtubules. Substrate motifs analysis indicates that TBK1 acts upstream of other essential cell cycle kinases like Aurora and PAK kinases. We also identified NAP1 as a TBK1 substrate at S318 promoting its degradation by ubiquitin proteasomal system acting as a negative regulatory step. These data uncover an important distinct function for the NAP1-TBK1 complex during cell division.

cell biology↗