Structural perspectives on linkers enabling cell-specific antibody-mediated targeted protein degradation

Loss-of-function studies are a central approach to understanding gene/protein function. In mice, this often relies upon heritable recombination at the DNA level. This approach is slow and nonreversible, which limits both spatial and temporal resolution of analysis. Recently, degron techniques that directly target proteins for degradation have been successfully used to quickly and reversibly knock down proteins. Currently, these systems have been limited by lack of tissue/cell type specificity. Here, we generated mice that allow spatial and temporal control of GFP-tagged protein degradation. This DegronGFP line leads to degradation of GFP-tagged proteins in different cellular compartments and in distinct cell types. Further, it is rapid and reversible. We used DegronGFP to probe the function of the glucocorticoid receptor in the epidermis and demonstrate that it has distinct functions in proliferative and differentiated cells-an analysis that would not have been possible with traditional recombination approaches. We propose that the ability to use GFP knock-in lines for loss-of-function analysis will provide additional motivation for generation of these useful tools.

SQSTM1/p62 is a master regulator of the autophagic and ubiquitination pathways of protein degradation and the antioxidant response. p62 functions in these pathways via reversible assembly and sequestration of additional factors into cytoplasmic phase-separated structures termed p62 bodies. The physiological roles of p62 in these various pathways depend on numerous mechanisms for regulating p62 body formation and dynamics that are incompletely understood. Here, we identify a new mechanism for regulation of p62 oligomerization and incorporation into p62 bodies by SHKBP1, a cullin-3 E3 ubiquitin ligase adaptor, that is independent of its potential functions in ubiquitination. We map an SHKBP1-p62 protein-protein interaction outside of p62 bodies that limits p62 assembly into p62 bodies and affects the antioxidant response involving sequestration of Keap1 and nuclear translocation of Nrf2. These studies provide a non-ubiquitination-based mechanism for an E3 ligase adaptor in regulating p62 body formation and cellular responses to oxidative stress.

PROteolysis TArgeting Chimeras are attracting growing interest in pharmaceutical research thanks to their catalytic and irreversible mechanism, which is capable of targeting proteins previously considered "undruggable". These bifunctional molecules hijack the cellular ubiquitin-proteasome system by recruiting E3 ligases (such as CRBN or VHL) to induce the selective degradation of a target protein. Their efficacy has been demonstrated against various disorders and several compounds have reached phase I-III clinical trials, reinforcing their appeal. In the fight against toxins, derivatives of the Retro-2 molecule (active against Shigatoxins, ricin, and various pathogens) have been developed. These molecules act on host cells by disrupting the intracellular trafficking of pathogens, targeting in particular the Sec16A and/or ASNA1 proteins. Our study presents the synthesis and characterization of new chemical probes based on PROTAC technology, combining a CRBN ligand derived from thalidomide, a Retro-2 derivative, and variable-length PEG chain linkers to better understand the mechanism of action of Retro-2-derived molecules. Contrary to initial assumptions, our results do not show proteasome-dependent degradation of the protein targets, but demonstrate that PEG-2 molecules can degrade the translation termination factor GSPT1 despite the normally propitious anchoring of the PEG linker at position 4 of the phthalimide ring. Furthermore, this study shows for the first time that GSPT1 degradation depends on the length of the flexible PEG chain linker.

UBE2D4 transcriptionally activated by YY1 drives G2/M progression through enhancing MDM2-dependent p53 degradation in glioma.

Oxidative profile and degradation patterns of plasma-activated water-treated golden pompano (Trachinotus ovatus) during chilled storage: Insights based on data independent acquisition (DIA) quantitative proteomics.

Contact-killing antimicrobial cationic starch/PBAT blown films: Physicochemical properties, antimicrobial mechanism, and preservation capacity on beef.

Cadmium-induced ATP6V0A1 destabilization impairs lysosomal function to disrupt hepatic lipid homeostasis.

TTC3-mediated ubiquitination of APPL1 is suppression involved in the anti-asthmatic effects of the substance P receptor antagonist WIN62577.

Targeted degradation of extracellular and membrane-associated proteins has emerged as a promising therapeutic modality. Here, we developed CD24-H7, a novel bispecific degrader that engages the transferrin receptor (TFRC) to mediate lysosomal degradation of CD24-an immunosuppressive protein commonly overexpressed in tumors. CD24-H7 consists of a TFRC-binding scFv and a CD24-specific scFv linked by a cathepsin-cleavable spacer, facilitating efficient internalization, lysosomal delivery, and subsequent recycling of TFRC. In vitro and in vivo experiments revealed potent and specific degradation of CD24, leading to marked suppression of tumor growth and enhanced antitumor immunity in humanized mouse glioblastoma (GBM) models. The degrader also exhibited a favorable safety profile with minimal on-target off-tumor toxicity. Moreover, combining CD24-H7 with anti-PD-1 antibodies synergistically promoted intratumoral CD8+ T cell infiltration and cytotoxicity while attenuating T cell exhaustion, resulting in significantly enhanced antitumor efficacy compared to monotherapy. These findings underscore the therapeutic potential of TFRC-recruiting degraders for selective targeting of membrane proteins and provide a compelling combinatorial approach to overcome immune evasion in oncology.

Semi-rigid linkers improve the pharmacokinetic properties and therapeutic efficacy of BET PROTACs for cancer therapy.

PRMT1 promotes H2O2 induced cardiomyocytes cell via mediating arginine methylation of P53.

Lupenone regulates LOXL2-mediated PANoptosis signaling through E3 ubiquitin ligases RNF168 to improve radiation-induced lung injury.

Alternating magnetic field-assisted freezing enhances the freeze-thaw stability of Pacific white shrimp (Litopenaeus vannamei): Evidence from physicochemical and metabolomic analyses.

A new era in targeted sEH therapy: strategic evolution from inhibition to protein degradation.

Why does EGFR-targeted therapy continue to fail in breast cancer? From mechanistic deciphering to novel intervention strategies.

PROTACs as novel therapeutics against Mycobacterium tuberculosis: Current progress and future directions.

Design and evaluation of selective BET PROTACs with potent antitumor efficacy and safety against acute myeloid leukemia.

LDOB: multi-dimensional programmable lactose-derived oligosaccharide biosensors.

A dCas9-integrated iLight9O system enables dynamic regulation for enhanced patchoulol biosynthesis in Saccharomyces cerevisiae.