Biology subjects

Vidak, S.

Publications and source records attributed to Vidak, S..

3 recordsLinked to original sources

bioRxiv2025

Transcriptional profiling of Hutchinson-Gilford Progeria patients identifies primary target pathways of progerin

Hutchinson Gilford Progeria Syndrome (HGPS) is an ultra-rare pediatric premature aging disorder. The disease is caused by a point mutation in the LMNA gene leading to the production of the dominant-negative progerin isoform of the nuclear envelope protein lamin A. Disease severity and progression amongst the population of [~]140 known patients is variable. Most of the mechanistic insights into the disease have come from studies using cellular or mouse models of HGPS. To probe the clinical relevance of previously implicated cellular pathways and to address the extent of gene expression heterogeneity between patients, we have performed transcriptomic analysis of a comprehensive set of HGPS patients. We find misexpression of several cellular pathways across the patient population, particularly of multiple signaling pathways as well as the Unfolded Protein Response (UPR) and mesodermal cell fate specification. Variability amongst individual patients was limited, with misregulation of the major pathways observed in most patients. Comparing the transcriptome of patients with an inducible HGPS cell model, we distinguished immediate-early cellular response pathways from secondary adaptive pathways and identified mTORC1, the UPR, UV response, apoptosis and TNF signaling via NF-{kappa}B as primary targets of the disease-causing progerin protein.

cell biology↗

bioRxiv2025

RNA-coupled CRISPR Screens Reveal ZNF207 as a Regulator of LMNA Aberrant Splicing in Progeria

Despite progress in understanding pre-mRNA splicing, the regulatory mechanisms controlling most alternative splicing events remain unclear. We developed CRASP-Seq, a method that integrates pooled CRISPR-based genetic perturbations with deep sequencing of splicing reporters, to quantitively assess the impact of all human genes on alternative splicing from a single RNA sample. CRASP-Seq identifies both known and novel regulators, enriched for proteins involved in RNA splicing and metabolism. As proof-of-concept, CRASP-Seq analysis of an LMNA cryptic splicing event linked to progeria uncovered ZNF207, primarily known for mitotic spindle assembly, as a regulator of progerin splicing. ZNF207 depletion enhances canonical LMNA splicing and decreases progerin levels in patient-derived cells. High-throughput mutagenesis further showed that ZNF207s zinc finger domain broadly impacts alternative splicing through interactions with U1 snRNP factors. These findings position ZNF207 as a U1 snRNP auxiliary factor and demonstrate the power of CRASP-Seq to uncover key regulators and domains of alternative splicing. Main PointsO_LICRASP-Seq: RNA-coupled CRISPR screen quantifying gene and domain impact on splicing C_LIO_LIProfiling of five events identified 370 genes influencing alternative splicing C_LIO_LIZNF207 regulates splicing by interacting with U1 snRNP via its zinc-finger domains C_LIO_LIZNF207 depletion corrects LMNA aberrant splicing causing progeria C_LI

genetics↗

bioRxiv2021

Activation of endoplasmic reticulum stress via clustering of inner nuclear membrane proteins

One of the major cellular mechanisms to ensure protein homeostasis is the endoplasmic reticulum (ER) stress response. This pathway is typically triggered by accumulation of misfolded proteins in the ER lumen. Here we describe activation of ER stress via protein aggregation in the cell nucleus. We find in the premature aging disease Hutchinson-Gilford Progeria Syndrome (HGPS) activation of ER stress due to the aggregation of the diseases-causing progerin protein at the nuclear envelope. The presence of nucleoplasmic protein aggregates is sensed and signaled to the ER lumen via immobilization and clustering of the inner nuclear membrane protein SUN2, leading to activation of the Unfolded Protein Response (UPR). These results identify a nuclear trigger of ER stress and they provide insight into the molecular disease mechanisms of HGPS.

cell biology↗