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Wolosker, H.

Publications and source records attributed to Wolosker, H..

3 recordsLinked to original sources

Cyclin D-CDK4/6 couple proliferation to membrane and mitochondrial protein supply through a DeSI1 phospho-switch

Cyclin D-CDK4/6 complexes drive cell-cycle entry through an RB-E2F-dependent transcriptional program, but how they coordinate proliferation with the membrane and organelle protein supply required for growth is unclear. We identify DeSI1 as a cyclin D-CDK4/6 substrate whose phosphorylation at S25 converts a latent homodimer into an active monomeric deubiquitylase that recognizes hydrophobic proteins such as those bearing transmembrane domains and mitochondrial targeting sequences. Phosphorylated DeSI1 extends the lifetime of newly synthesized hydrophobic proteins that support membrane and mitochondrial capacity. Constitutive DeSI1 activation uncouples this proteostatic program from metabolic supply, creating a cytidine-nucleotide supply-demand imbalance associated with impaired CTP-dependent phospholipid homeostasis, cardiolipin depletion, and mitochondrial decompensation - defects that cytidine reverses. In mice, constitutive DeSI1 activation causes progressive cerebellar degeneration with membrane-protein accumulation, respiratory-chain loss, and phospholipid depletion. These findings define a post-translational mechanism coupling cell-cycle entry to membrane and mitochondrial capacity, and reveal the cost of uncoupling this program from its metabolic support.

cell biology↗

Developmental Bioenergetic Reprogramming and Glycolytic Shift in Schizophrenia Vulnerability

Schizophrenia (SZ) arises from complex gene-environment interactions, yet how early insults shape later circuit vulnerability remains unclear. Here, we investigated whether bioenergetic states represent a convergent disease signature across genetic and environmental risk factors. We analyzed transcriptional profiles across neocortical development in murine models of maternal immune activation (polyIC MIA), and serine racemase deletion (Srr-/-), extending these analyses to juvenile stages in Srr-/- and interneuron-specific NMDA receptor deletion (Nkx2.1:Grin1fl/fl), highlighting cell-type-specific metabolic vulnerability across developmental stages. In MIA, early gestation (E12.5) revealed a transient bioenergetic shift likely driven by microglial and radial glial populations, suggesting metabolic priming rather than canonical inflammatory signaling. By late gestation (E17.5), MIA induced coordinated dysregulation of neuronal glycolytic isoforms alongside mitochondrial and lipid-associated metabolic pathways, suggesting coordinated metabolic remodeling involving lipid-linked processes. In contrast, Srr-/- mice showed minimal glycolytic alterations at E17.5, indicating that isolated genetic perturbation is insufficient to recapitulate this fetal metabolic state. However, at juvenile stages, region-specific bioenergetic adaptations emerged. Srr-/- mice exhibited global cortical increases in glycolytic gene expression, with hippocampal changes potentially enriched in neuronal populations. Conversely, Nkx2.1:Grin1fl/flinterneurons showed increased glycolytic and TCA cycle transcription in the hippocampus but opposing patterns in the medial prefrontal cortex. Together, these findings identify increased glycolytic activity, potentially linked to lactate metabolism, as a partially convergent developmental mechanism bridging prenatal perturbations and later circuit dysfunction in SZ, and suggest that downstream glycolysis-linked pathways may contribute to phenotypic heterogeneity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=174 SRC="FIGDIR/small/723970v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@1dd1461org.highwire.dtl.DTLVardef@1651b65org.highwire.dtl.DTLVardef@e98bc8org.highwire.dtl.DTLVardef@d813a2_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Dysregulation of Multiple Solute Carrier genes and Metabolic Deficits in SLC1A4-Mutant Human iPSC-Derived Hippocampal Neurons

Mutations in SLC1A4, which encodes the neuronal amino acid transporter ASCT1, disrupt metabolic and synaptic homeostasis, contributing to neurodevelopmental deficits commonly observed in autism spectrum disorder (ASD). To investigate the underlying molecular mechanisms of SLC1A4-related disorders, we utilized human iPSC-derived hippocampal neurons and applied an integrated multi-omics approach, combining electrophysiology, calcium imaging, metabolomics, proteomics, and transcriptomics. Our findings reveal an initial phase of early neuronal hyperexcitability, driven by increased sodium and potassium currents, followed by a progressive decline in synaptic activity at later stages. Metabolomic analysis identified elevated glycine, serine, and glutamate levels during early differentiation, contributing to excitotoxicity, whereas later glutamate depletion and extracellular matrix (ECM) disruption were associated with synaptic dysfunction. Proteomics data further showed dysregulation in metabolic pathways, amino acid biosynthesis, and fatty acid metabolism pathways during early time points, and in later stage dysregulation in metabolic and ECM-receptor interactions. Additionally, transcriptomic analysis revealed dysregulation in calcium signaling, amino acid metabolism pathways such as valine, leucine and isoleucine degradation, tryptophan metabolism, and glycine, serine, and threonine metabolism. Further investigation of SLC-family transporter genes uncovered disruptions in glutamate and glycine transport, establishing a direct link between amino acid transport dysfunction and neuronal deficits. Collectively, our study demonstrates that SLC1A4 mutations lead to dysregulation of multiple solute carrier protein genes causing metabolic stress, excitability defects, and synaptic abnormalities, providing a molecular framework for understanding SLC1A4-related neurodevelopmental disorders and identifying potential therapeutic targets.

neuroscience↗