Biology subjects

Wojtowicz, T.

Publications and source records attributed to Wojtowicz, T..

8 recordsLinked to original sources

bioRxiv2026

Spatial learning-specific remodeling of the hippocampal palmitoylome

Protein S-palmitoylation is a reversible lipid modification that regulates protein trafficking, membrane association, and synaptic signaling, yet its role in learning-induced neuronal plasticity remains incompletely understood. Here, we investigated how spatial learning remodels the hippocampal palmitoylome in rats trained in the Morris water maze using short-term (STT; one session, 15 trials; probe at 1 h) or long-term (LTT; four sessions over four days; probe at 24 h) paradigms. Palmitoylated proteins were profiled by acyl-biotin exchange coupled with tandem mass tag labeling and LC-MS/MS. We identified 5,260 proteins, including 763 palmitoylated species. Spatial learning induced extensive remodeling of protein S-palmitoylation, with markedly greater changes after STT than LTT. Using yoked controls, we distinguished palmitoylation changes associated with learning the hidden platform location from those induced by general behavioral experience. Comparison of trained and yoked animals identified 186 and 62 differentially palmitoylated proteins after STT and LTT, respectively, whereas yoked animals also exhibited extensive changes relative to naive controls, demonstrating that behavioral experience alone substantially reshapes the hippocampal palmitoylome. Functional enrichment revealed that STT preferentially engaged pathways related to synaptic transmission, cytoskeletal remodeling, GTPase signaling, and cellular metabolism, whereas LTT was associated with protein translation and synaptic organization. Site-specific analysis identified numerous previously unreported palmitoylation sites. Hierarchical analysis further identified diacylglycerol lipase- (DAGLA) as the only protein whose palmitoylation consistently reflected both general Morris water maze experience and learning the hidden platform location across both paradigms. Together, these findings establish S-palmitoylation as a dynamic regulator of experience-dependent hippocampal plasticity.

neuroscience↗

bioRxiv2025

Temporal and protein-specific S-palmitoylation supports synaptic and neural network plasticity

S-palmitoylation, a dynamic post-translational modification, has long been suggested to play a pivotal role in synaptic plasticity, learning, and memory. However, its precise impact on synaptic proteins and function remains unclear. In this study, we show that acute protein depalmitoylation in the hippocampus differentially affects short- and long-term synaptic plasticity, depending on synapse type. Strikingly, depalmitoylation also reprograms neuronal spiking timing following associative network activation. Our research identifies pre- and postsynaptic proteins dynamically regulated by S-palmitoylation during synaptic plasticity and suggests this modification occurs in isolated excitatory synapses. We also demonstrate that S-palmitoylation targets specific proteins within minutes and is not proteome-wide. These findings mark a significant advance in understanding how lipid modifications drive neural adaptability, memory, and learning.

neuroscience↗

bioRxiv2024

Terminal nucleotidyltransferase Tent2 microRNA tailing regulates excitatory/inhibitory balance in the hippocampus

One of the post-transcriptional mechanisms regulating the stability of RNA molecules involves the addition of non-templated nucleotides to their 3 ends, a process known as RNA tailing. To systematically investigate the physiological consequences of terminal nucleotidyltransferase TENT2 absence on RNA 3 end modifications in the mouse hippocampus we developed a new Tent2 knockout mouse. Electrophysiological measurements revealed increased excitability in Tent2 KO hippocampal neurons, and behavioral analyses showed decreased anxiety and improved fear extinction in these mice. At the molecular level, we observed a significant contribution of TENT2 to the monoadenylation of various classes of miRNAs, but found no effect of the enzymes loss on the total poly(A) tail length of mRNAs, as measured by Direct Nanopore RNA sequencing. Alterations in monoadenylation of a large population of microRNAs affected the overall mRNA abundance, particularly transcripts related synaptic transmission, which were downregulated in the hippocampus of Tent2 knockout mice. These changes explain the observed behavioral and electrophysiological alterations. Our data thus establish a link between TENT2-dependent microRNA tailing and the balance of inhibitory and excitatory neurotransmission.

neuroscience↗

bioRxiv2023

Mutation in mitochondrial chaperone TRAP1 results in male-specific autism

There is increasing evidence of mitochondrial dysfunction in autism spectrum disorders (ASD), but the causal relationships are unclear. In an ASD patient whose identical twin was unaffected, we identified a postzygotic mosaic mutation p.Q639* in the TRAP1 gene, which encodes a mitochondrial chaperone of the HSP90 family. Additional screening of 176 unrelated ASD probands revealed an identical TRAP1 variant in a male patient who had inherited it from a healthy mother. Notably, newly generated knock-in Trap1 p.Q641* mice display ASD-related behavioral abnormalities exclusively in males. Accordingly, Trap1 p.Q641* mutation also resulted in sex-specific changes in synaptic plasticity, number of presynaptic mitochondria, and metabolic substrate consumption. Thus, the TRAP1 p.Q639* mutation is the first example of a monogenic ASD caused by impaired mitochondrial protein homeostasis. One-Sentence SummaryPatient mutation in TRAP1 causes autism in male mice.

neuroscience↗

bioRxiv2023

Phosphorylation of PSD-95 at Serine 73 in dCA1 is required for extinction of contextual fear

The updating of contextual memories is essential for survival in a changing environment. Accumulating data indicate that the dorsal CA1 area (dCA1) contributes to this process. However, the cellular and molecular mechanisms of contextual fear memory updating remain poorly understood. Postsynaptic density protein 95 (PSD-95) regulates the structure and function of glutamatergic synapses. Here, using dCA1-targeted genetic manipulations in vivo, combined with ex vivo 3D electron microscopy and electrophysiology, we identify a novel, synaptic mechanism that is induced during attenuation of contextual fear memories and involves phosphorylation of PSD-95 at Serine 73 in dCA1. Our data provide the proof that PSD-95-dependent synaptic plasticity in dCA1 is required for updating of contextual fear memory.

neuroscience↗

bioRxiv2022

The molecular fingerprint of stress resilience

Stress resilience is the ability of neuronal networks to maintain their function despite the stress exposure. Using a mouse model we here investigate stress resilience phenomenon. To assess the resilient and anhedonic behavioral phenotypes developed after the induction of chronic unpredictable stress, we quantitatively characterized the structural and functional plasticity of excitatory synapses in the hippocampus using a combination of proteomic, electrophysiological, and imaging methods. Our results indicate that stress resilience is an active and multifactorial process manifested by structural, functional, and molecular changes in synapses. We reveal that chronic stress influences palmitoylation of synaptic proteins, whose profiles differ between resilient and anhedonic animals. The changes in palmitoylation are predominantly related with the glutamate receptor signaling thus affects synaptic transmission and associated structures of dendritic spines. We show that stress resilience is associated with structural compensatory plasticity of the postsynaptic parts of synapses in CA1 subfield of the hippocampus. One Sentence SummaryCompensatory remodeling of dendritic spines at the structural and molecular levels underlies stress resilience.

neuroscience↗

bioRxiv2020

PSD-95 in dorsal CA1 contributes to the persistence of fear memory

The ability to extinguish fearful memories is essential for survival. Accumulating data indicate that the dorsal CA1 area (dCA1) contributes to this process. However, the cellular and molecular basis of fear memory extinction remains poorly understood. Postsynaptic density protein 95 (PSD-95) regulates the structure and function of glutamatergic synapses. Here, using dCA1-targeted genetic and chemogenetic manipulations in vivo combined with PSD-95 immunostaining and 3D electron microscopy ex vivo, we demonstrate that phosphorylation of PSD-95 at serine 73 PSD-95(S73) is necessary for contextual fear extinction-induced expression of PSD-95 and synaptic plasticity. Moreover, PSD-95(S73) phosphorylation is not necessary for fear memory formation and recall but is required for extinction of contextual fear. Overall, our data shows how PSD-95-dependent synaptic plasticity in the hippocampus contributes to the persistence of fear memories.

neuroscience↗

bioRxiv2018

Stress-induced changes in the S-palmitoylation and S-nitrosylation of synaptic proteins

The precise regulation of synaptic integrity is critical for neuronal network connectivity and proper brain function. Essential aspects of the activity and localization of synaptic proteins are regulated by posttranslational modifications. S-palmitoylation is a reversible covalent modification of the cysteine with palmitate. It modulates affinity of the protein for cell membranes and membranous compartments. Intracellular palmitoylation dynamics are regulated by other posttranslational modifications, such as S-nitrosylation. Still unclear, however, are the ways in which this crosstalk is affected in brain pathology, such as stress-related disorders. Using a newly developed mass spectrometry-based approach (Palmitoylation And Nitrosylation Interplay Monitoring), we analyzed the endogenous S-palmitoylation and S-nitrosylation of postsynaptic density proteins at the level of specific single cysteines in a mouse model of chronic stress. Our results suggest that atypical mechanism of crosstalk between the S-palmitoylation and S-nitrosylation of synaptic proteins might be one of the major events associated with chronic stress disorders.

neuroscience↗