Biology subjects

Pavenstädt, H.

Publications and source records attributed to Pavenstädt, H..

3 recordsLinked to original sources

bioRxiv2026

Molecular orchestration of global actin remodelling by INF2

The actin cytoskeleton rapidly reorganizes in response to intracellular calcium signals, driving cellular morphogenesis and wound healing. Among actin regulators, the formin INF2 uniquely mediates the "Calcium-mediated Actin Reset" (CaAR) reaction, orchestrating transient and global actin remodeling upon calcium influx. Excessive INF2 activity is linked to kidney and neuronal diseases, underscoring the need for its tight control. Combining live cell imaging with single molecule tracking, biochemistry and structural analysis we discover that INF2 activity is tightly controlled by two interlinked mechanisms: canonical intramolecular autoinhibition and binding of the INF2 N-terminus to the side of actin filaments. Side-binding limits actin elongation and supports re-establishment of autoinhibition. Disruption of this negative feedback prolongs INF2 activity, affecting plasma membrane organization and repair as well as transcriptional control. Our findings uncover a novel product-inhibition mechanism that limits INF2 function and offer important insight into disease mechanisms linked to actin dysregulation.

cell biology↗

bioRxiv2025

CRISPR-Cas9 HDR Optimization: RAD52, Denatured and 5'-Modified DNA Templates in Knock-In Mice Generation

AbstractCRISPR/Cas9-mediated genome editing is a powerful tool for producing animal models of human diseases. However, it often encounters challenges related to low efficiency of donor DNA templates insertion through homology-directed repair (HDR) pathway or unwanted insertions and/or multiplications. Here, we present findings from multiple targeting experiments aimed at generating a Nup93 conditional knockout (cKO) mouse model. Injection of CRISPR/Cas9 components into over two thousand zygotes, resulted in 270 founder animals. Our study revealed various obstacles associated with the use of single-stranded (ssDNA) and double-stranded DNA (dsDNA) templates during cKO generation, highlighting the critical role of denaturation of long 5-monophosphorylated dsDNA templates in enhancing precise genome editing and reducing template multiplications. Application of RAD52 protein increased HDR efficiency of ssDNA integration almost 4-fold, albeit with an associated increase in template multiplication. Targeting the antisense strand of DNA using two crRNAs demonstrated better efficacy in HDR-mediated precise genome editing when compared to targeting the sense or sense-antisense strands. In addition, the application of 5-end biotin-modified donor DNA resulted in up to a 8-fold increase in HDR-mediated single-copy template integration compered to unmodified dsDNA donor. Furthermore, application of 5-end C3 spacer modified template resulted in up to a 20-fold increase in correctly HDR modified mice independent from ssDNA or dsDNA template employment. This study underscores potential pitfalls in CRISPR/Cas9-mediated genome editing and offers simple practical solutions to refine this potent tool. These findings highlight various strategies to enhance CRISPR/Cas9 HDR efficiency, providing a framework for improving precision in the generation of conditional knockout models.

molecular biology↗

bioRxiv2019

A deregulated stress response underlies distinct INF2 associated disease profiles

Monogenic diseases provide favorable opportunities to elucidate the molecular mechanisms of disease progression and improve medical diagnostics. However, the complex interplay between genetic and environmental factors in disease etiologies makes it difficult to discern the mechanistic links between different alleles of a single locus and their associated pathophysiologies. Here we systematically characterize a large panel (>50) of autosomal dominant mutants of the actin regulator inverted formin 2 (INF2) that have been reported to cause the podocytic kidney disease focal segmental glomerulosclerosis (FSGS) and the neurological disorder Charcot Marie-Tooth disease (CMT). We found that INF2 mutations lead to deregulated activation of the formin and a constitutive stress response in cultured cells, primary patient cells and Drosophila nephrocytes. Using quantitative live-cell imaging we were able to identify distinct subsets of INF2 variants that exhibit varying degrees of activation. Furthermore, we could clearly distinguish between INF2 mutations that were linked exclusively to FSGS from those that caused a combination of FSGS and CMT. Our results indicate that cellular profiling of disease-associated mutations can contribute substantially to sequence-based phenotype predictions.

cell biology↗