Biology subjects

Schmiderer, L.

Publications and source records attributed to Schmiderer, L..

4 recordsLinked to original sources

bioRxiv2026

De novo design of selective kinase modulators

Protein kinases are critical regulators of cellular signaling, but precise modulation of their activity remains challenging due to their high structural conservation. Here, we present de novo designed genetically encoded miniproteins capable of activating or inhibiting focal adhesion kinase (FAK) by directly targeting the kinase domain itself. Among 96 binders designed to stabilize distinct conformational states of FAK, 33 modulated kinase activity. Biochemical characterization of the four most potent modulators revealed that two designs inhibit FAK with low-nanomolar IC50 values while the remaining two potentiated FAK activity by more than two-fold. When expressed in cells, the modulators preserved the same inhibitory and activating effects observed in vitro, establishing that designed conformational binders can directly tune FAK signaling in living cells. Taking advantage of the high similarity between kinases, we redesigned the FAK inhibitors to inhibit Src kinase. Our approach establishes a versatile platform for selective and genetically encoded kinase control as a way to rewire cell signaling and as a starting point for the discovery of novel modulatory sites of kinases.

biochemistry↗

bioRxiv2026

TFU72 is a novel and potent DNA-PKcs inhibitor for enhancing homology-directed repair gene editing

Precise gene editing through homology directed repair (HDR) is one of the most versatile genome editing approaches with broad applications. Achieving high HDR gene editing efficiency is critical to realizing the full potential of this approach. Although many strategies have been explored to enhance HDR editing efficiency, inhibition of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a key component of the non-homologous end joining (NHEJ) pathway remains one of the most effective. Here we describe a novel, highly potent DNA-PKcs small molecule inhibitor, TFU72 which enhances HDR gene editing efficiency remarkably by up to 30-fold in cell lines and human primary cells. We assessed the previously reported genotoxic outcomes associated with DNA-PKcs inhibition such as off-target mutations, chromosomal translocations and large deletions and describe approaches to mitigate these outcomes to safely enhance HDR gene editing efficiency with TFU72. This optimized approach enables broad application of TFU72 for HDR-based precise gene editing applications in both therapeutic and research settings.

molecular biology↗

bioRxiv2025

Lithography-free Water Stable Conductive Polymer Nanowires

Free-standing nanowires can gain intracellular access without causing cellular stress or apoptosis. Current approaches to generate nanowires focus on lithographic patterning and inorganic materials (Si, GaAs, Al2O3, etc.) while organic materials are less explored. Use of organic conductive polymers allows for creation of soft mixed ion-electron conducting nanowires. Processing conductive polymers into nanowires is challenging due to the harsh chemicals and processing conditions used. Here, we demonstrate a lithography-free and scalable method to generate all-organic water-stable nanowires composed of conductive polymers. A nanoporous membrane is filled with conductive polymer in solution followed by a cross-linking step to make the polymer water stable. The surface of the membrane is anisotropically etched using a reactive ion etcher to reveal the polymer inside the pores, which extend from the membrane as nanowires. We interface the nanowires with model algal cells and human primary hematopoietic stem and progenitor cells. TOC Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/631660v1_ufig1.gif" ALT="Figure 1"> View larger version (56K): org.highwire.dtl.DTLVardef@bf44b3org.highwire.dtl.DTLVardef@13782baorg.highwire.dtl.DTLVardef@1679366org.highwire.dtl.DTLVardef@fe1677_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

bioRxiv2022

Inducing synthetic lethality for selective targeting of acute myeloid leukemia cells harboring STAG2 mutations

Targeted therapies exploiting selective vulnerabilities of malignant cells are highly desired for clinical applications. The cohesin protein complex comprises of RAD21, SMC3, SMC1A as well as a fourth subunit that consists of either STAG1 or STAG2 and is essential for proper chromosomal segregation during mitosis. STAG2 loss-of-function mutations are recurrent driver events in acute myeloid leukemia (AML) and appear relatively early during leukemogenesis. Studies in cell lines have shown that STAG2 deficient cells are uniquely vulnerable to STAG1 perturbation, and this vulnerability could thus be exploited to selectively eliminate STAG2 null AML cells. Here we show that partial perturbation of STAG1 is well tolerated by normal human hematopoietic stem cells and does not affect their functionality. By contrast, STAG1 knockdown is lethal to STAG2 null human HSCs by inducing major mitotic defects. Moreover, STAG1 knockdown induced synthetic lethality in primary human AML cells harboring a STAG2 mutation and completely abrogated leukemia progression in xenograft models. Overall, our study provides proof-of-concept demonstration of a synthetic lethal approach to selectively target primary human cancer cells with STAG2 mutations

cancer biology↗