Biology subjects

Weick, J. P.

Publications and source records attributed to Weick, J. P..

4 recordsLinked to original sources

bioRxiv2025

The protein interactome of the Neuron Specific Gene family (NSG1-3)

The Neuron-Specific Gene (NSG) family members (NSG1-3) play critical and diverse roles in neuronal protein trafficking, but their precise molecular functions remain poorly understood. Here, we employed proximity-labeling proteomics to map the interactomes of each NSG protein. Unlabeled mass spectrometry identified over 1,000 significantly enriched interactors compared with a cytoplasmic control, revealing substantial overlap between NSG1 and NSG2, and a more divergent profile for NSG3. Gene ontology and KEGG pathway analysis confirmed established associations with glutamatergic synapses and endosomal trafficking, while also uncovering unexpected links to presynaptic machinery, inhibitory synapses, and endoplasmic reticulum-associated protein translation, particularly for NSG3. Reciprocal biotinylation patterns and co-immunoprecipitation revealed novel heteromeric complex formation between NSG1 and NSG2, with limited interactions involving NSG3. All three NSGs biotinylated core AMPA receptor subunits and auxiliary proteins, while NSG1 and NSG2 also associated with NMDA receptors, GABA receptor subunits, as well as multiple presynaptic proteins. Moreover, NSG1 and NSG2 specifically biotinylated components of multiunit tethering complexes including neuron-specific retromer, and biotinylated a preponderance of ADAM10 substrates, reinforcing their role in proteolytic processing. Finally, despite the relatively divergent interactomes of NSG1 and NSG2 compared to NSG3, all family members robustly biotinylated amyloid precursor protein (APP), suggesting possible synergistic or competitive interactions that could shape APP proteolytic processing and/or trafficking. Together, these data provide a comprehensive systems-level view of NSG protein interactions, establishing a molecular framework for future investigations into NSG-mediated neural plasticity and disease mechanisms.

neuroscience↗

bioRxiv2024

Knockout of AMPA receptor binding protein Neuron-Specific Gene 2 (NSG2) enhances associative learning and cognitive flexibility

The vast majority of gene mutations and/or gene knockouts result in either no observable changes, or significant deficits in molecular, cellular, or organismal function. However, in a small number of cases, mutant animal models display enhancements in specific behaviors such as learning and memory. To date, most gene deletions shown to enhance cognitive ability generally affect a limited number of pathways such as NMDA receptor- and translation-dependent plasticity, or GABA receptor- and potassium channel-mediated inhibition. While endolysosomal trafficking of AMPA receptors is a critical mediator of synaptic plasticity, mutations in genes that affect AMPAR trafficking either have no effect or are deleterious for synaptic plasticity, learning and memory. NSG2 is one of the three-member family of Neuron-specific genes (NSG1-3), which have been shown to regulate endolysosomal trafficking of a number of proteins critical for neuronal function, including AMPAR subunits (GluA1-2). Based on these findings and the largely universal expression throughout mammalian brain, we predicted that genetic knockout of NSG2 would result in significant impairments across multiple behavioral modalities including motor, affective, and learning/memory paradigms. However, in the current study we show that loss of NSG2 had highly selective effects on associative learning and memory, leaving motor and affective behaviors intact. For instance, NSG2 KO animals performed equivalent to wild-type C57Bl/6n mice on rotarod and Catwalk motor tasks, and did not display alterations in anxiety-like behavior on open field and elevated zero maze tasks. However, NSG2 KO animals demonstrated enhanced recall in the Morris water maze, accelerated reversal learning in a touch-screen task, and accelerated acquisition and recall on a Trace Fear Conditioning task. Together, these data point to a specific involvement of NSG2 on multiple types of associative learning, and expand the repertoire of pathways that can be targeted for cognitive enhancement.

neuroscience↗

bioRxiv2020

X-ray mediated scintillation increases synaptic activity via Cerium-doped LSO and Channelrhodopsin-2

Optogenetics is a widely used tool for studying neural circuits. However, non-invasive methods for light delivery in the brain are needed to avoid physical damage typically caused by intracranial insertion of light guides. An innovative strategy could employ X-ray activation of radioluminescent particles (RLPs) to emit localized light. We previously reported that RLPs composed of cerium doped lutetium oxyorthosilicate (LSO:Ce), an inorganic scintillator that emits blue light, are biocompatible with neuronal function and synaptic transmission. However, little is known about the consequences of acute X-ray exposure on synaptic function and long-term plasticity. Furthermore, modulation of neuronal or synaptic function by X-ray induced radioluminescence from RLPs has not yet been demonstrated. Here we show that 30 minutes of X-ray exposure at a rate of 0.042 Gy/second caused no change in the strength of basal glutamatergic transmission during extracellular dendritic field recordings in mouse hippocampal slices. Additionally, long-term potentiation (LTP), a robust measure of synaptic integrity, was able to be induced after X-ray exposure and expressed at a magnitude not different from control conditions (absence of X-rays). This is important as synaptic plasticity is critical to learning and memory. Next, we used molecular and electrophysiological approaches to determine if X-ray dependent radioluminescence emitted from RLPs can activate light sensitive proteins. We found that X-ray stimulation of RLPs elevated cAMP levels in HEK293T cells expressing OptoXR, a chimeric opsin receptor that combines the extracellular light-sensitive domain of channelrhodopsin-2 (ChR2) with an intracellular second messenger signaling cascade. This demonstrates that X-ray radioluminescence from LSO:Ce particles can activate OptoXR. Next, we tested whether X-ray activation of the RLPs can enhance synaptic activity in whole-cell recordings from hippocampal neurons expressing ChR2, both in cell culture and acute hippocampal slices. Importantly, X-ray radioluminescence caused an increase in the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) in both systems, indicating activation of ChR2 and excitation of neurons. Together, our results show that X-ray activation of LSO:Ce particles can heighten cellular and synaptic function. The combination of LSO:Ce inorganic scintillators and X-rays is therefore a viable method for optogenetics as an alternative to more invasive light delivery methods.

neuroscience↗

bioRxiv2019

Transcriptomic changes due to early, chronic ethanol exposure during cortical development implicates arealization, cell-type specification, Axon Guidance and Synaptogenesis as primary determinants of Fetal Alcohol Spectrum Disorders

Fetal alcohol spectrum disorders (FASD) are described by a cluster of deficits following in utero alcohol exposure, whose effects disproportionately target the cerebral cortex. In vitro and in vivo models of FASD have successfully recapitulated multiple facets of clinical presentations, including morphological and behavioral deficits, but far less is understood regarding the molecular and genetic bases of FASD. In this study, we utilize an in vitro human pluripotent stem cell-based (hPSC) model of corticogenesis to probe the effect of early, chronic alcohol exposure on the transcriptome of developing cortical neurons. We here identify a relatively limited number of significantly altered biological pathways, including regional patterning, cell-type specification, axon guidance and synaptic function. Significant upregulation of WNT signaling-related transcripts, to the exclusion of other secreted morphogens was also observed in alcohol exposed cultures. Lastly, an overall alcohol-associated shift towards an increased caudal profile, at the expense of rostral molecular identity was observed, representing a potentially previously underappreciated FASD phenotype.

neuroscience↗