Tiwari, P. K. | bioRxiv Science

bioRxiv2025

R allele of ACTN3 R577X gene polymorphism is associated with Elite Indian Boxer Status

Genetic variations are considered important for athletic performance. In this regard, polymorphisms in angiotensin I-converting enzyme (ACE) and -actinin-3 genes are widely studied for their association with elite athlete status. The ACE gene regulates circulatory homeostasis, with the I variant of the ACE insertion/deletion (ACE I/D) gene polymorphism being associated with endurance performance, while the R allele of the R577X polymorphism of the ACTN3 gene, crucial for fast glycolytic muscle fibers, has been associated with speed and power performances. The present study investigated the association of these genetic variants with elite boxer (N=57) status and compared it with elite power/speed athletes (N=40), endurance athletes (N=44) and nonathletes (N=98) in the Indian population. The R allele frequency was found significantly higher in boxers than the nonathletes (p < 0.05). The allele and genotype frequencies of boxers, endurance and power/speed athletes did not differ significantly (p > 0.05). After analyzing overall athletic cohort on the basis of their level of performance, the frequency of RR genotype (24.1%) and R allele (47.7%) in national level athletes was found significantly higher than in nonathletes (8.7% and 34.2%, respectively), with the significant difference (p < 0.05) between national level endurance athletes and nonathletes only. The ACE I/D gene polymorphism was not found associated with any of the athletic cohorts (p > 0.05). Taken altogether, our study showed that the R allele of ACTN3 gene polymorphism is associated with elite boxer status as compared to the nonathletes. HighlightsO_LIBoxers had a higher ACTN3 gene R allele frequency than nonathletes; genotype did not differ. C_LIO_LIBoxers with RR genotype had more than 3x higher odds versus nonathletes (p = 0.02) in the X dominant model (RR vs RX+XX). C_LIO_LIACTN3 gene allele and genotype frequencies differed between overall athletic cohort and nonathletes. C_LIO_LIACE gene frequencies showed no difference or association across athletic cohorts. C_LI

genetics↗

bioRxiv2021

Proteolysis Targeting Chimeras With Reduced Off-targets

Proteolysis Targeting Chimeras (PROTACs), a class of heterobifunctional molecules that recruit target proteins to E3 ligases, have gained traction for targeted protein degradation. However, pomalidomide, a widely used E3 ligase recruiter in PROTACs, can independently degrade other targets, such as zinc-finger (ZF) proteins, that hold key functions in normal development and disease progression. This off-target degradation of pomalidomide-based PROTACs raises concerns about their therapeutic applicability and long-term side effects. Therefore, there is a crucial need to develop rules for PROTAC design that minimize off-target degradation. In this study, we developed a high-throughput platform that interrogates the off-target degradation of ZF domains and discovered, using this platform, that PROTACs with the current design paradigm induce degradation of several ZF proteins. To identify new rules for PROTAC design, we generated a library of pomalidomide analogs that allowed systematic exploration of the impact of positional isomerism (e.g., C4 and C5 positions of the phthalimide ring), hydrogen bonding, steric and hydrophobic effects on propensities for ZF protein degradation. We found that modifications of appropriate size on the C5 position reduced off-target ZF degradation. We validated these results using immunoblotting, target engagement, and global mass spectrometric studies. We applied our newfound design principles on a previously developed ALK oncoprotein-targeting PROTAC and generated PROTACs with enhanced potency and minimal off-target degradation. We envision the reported off-target profiling platform and pomalidomide analogs will find utility in design of specific PROTACs.

pharmacology and toxicology↗