Biology subjects

Rode, S.

Publications and source records attributed to Rode, S..

4 recordsLinked to original sources

bioRxiv2025

The UAP56 mRNA Export Factor is Required for Dendrite and Synapse Pruning via Actin Regulation in Drosophila

Neurite and synapse pruning are conserved mechanisms that adapt neuronal circuitry to different developmental stages. Drosophila sensory c4da neurons prune their larval dendrites and their presynaptic terminals during metamorphosis using a gene expression programme that is induced by the steroid hormone ecdysone and involves posttranscriptional regulation pathways. Here we show that loss of the helicase UAP56, an important mediator of nuclear mRNA export, causes strong dendrite and presynapse pruning defects. Loss of UAP56 is linked to actin regulation, as it causes defects in the expression of the actin severing enzyme Mical during dendrite pruning, and actin accumulation at presynapses, where cofilin is required for pruning. Our findings suggest specificity in mRNA export pathways and identify a role for actin disassembly during presynapse pruning.

neuroscience↗

bioRxiv2020

Negatively charged peptide nanofibrils from immunoglobulin light chain sequester viral particles but lack cell-binding and viral transduction-enhancing properties

Positively charged naturally occurring or engineered peptide nanofibrils (PNF) are effective enhancers of lentiviral and retroviral transduction, an often rate limiting step in gene transfer and gene therapy approaches. These polycationic PNF are thought to bridge the electrostatic repulsions between negatively charged membranes of virions and cells, thereby enhancing virion attachment to and infection of target cells. Here, we analyzed PNF which are formed by the peptide AL1, which represents a fragment of an immunoglobulin light chain that causes systemic AL amyloidosis. We found that negatively charged AL1 PNF interact with viral particles to a comparable extent as positively charged PNF. However, AL1 PNF lacked cell binding activity and consequently did not enhance retroviral infection. These findings show that virion capture and cell binding of PNF are mediated by different mechanisms, offering avenues for the design of advanced PNF with selective functions.

cell biology↗

bioRxiv2020

Cellular Protrusions Engage Viral Infection Enhancing EF-C Peptide Nanofibrils

Self-assembling peptide nanofibrils (PNF) have gained increasing attention as versatile molecules in material science and biomedicine. One important application of PNF is to enhance retroviral gene transfer, a technology that has been central to the development of gene therapy. The best-investigated and commercially available PNF is derived from a 12-mer peptide termed EF-C. The mechanism of transduction enhancement depends on the polycationic surface of EF-C PNF, which binds to the negatively charged membranes of viruses and cells thereby overcoming electrostatic repulsion and increasing virion attachment and fusion. Assuming an even distribution of charges at the surfaces of virions and cells would result in an evenly distributed interaction of the virions with the cell surface. However, we here report that PNF do not randomly bind at the cell surface but are actively engaged by cellular protrusions. Chemical suppression of protrusion formation in cell lines and primary CD4+ T cells greatly reduced fibril binding and hence virion binding. Thus, the mechanism of PNF-mediated viral transduction enhancement involves active engagement of virus-loaded fibrils by cellular protrusions.

cell biology↗

bioRxiv2019

Diachronic monitoring of snow leopards at Sarychat-Ertash State Reserve (Kyrgyzstan) through scat genotyping: a pilot study

Snow leopards (Panthera uncia) are a keystone species of Central Asias high mountain ecosystem. The species is listed as vulnerable and is elusive, preventing accurate population assessments that could inform conservation actions. Non-invasive genetic monitoring conducted by citizen scientists offers avenues to provide key data on this species that would otherwise be inaccessible. From 2011 to 2015, OSI-Panthera citizen science expeditions tracked signs of presence of snow leopards along transects in the main valleys and crests of the Sarychat-Ertash State Reserve (Kyrgyzstan). Scat samples were genotyped at seven autosomal microsatellite loci and at a X/Y locus for sex identification, which allowed estimating a minimum of 11 individuals present in the reserve from 2011 to 2015. The genetic recapture of 7 of these individuals enabled diachronic monitoring, providing indications of individuals movements throughout the reserve. We found putative family relationships between several individuals. Our results demonstrate the potential of this citizen science program to get a precise description of a snow leopard population through time.

genetics↗