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Ruszkowski, M.

Publications and source records attributed to Ruszkowski, M..

2 recordsLinked to original sources
bioRxiv2026

Loss of a conserved disulfide bond defines Penetration2-related immune myrosinases in Brassicaceae

O_LIThis study investigated whether PEN2/BGLU26 has uniquely evolved as an indole glucosinolate-hydrolysing myrosinase required for Arabidopsis thaliana pre-invasive immunity, or whether related myrosinases can replace its function when targeted to the same subcellular context. C_LIO_LIPEN2-homologous and other selected myrosinases from A. thaliana and Brassica rapa were expressed in the pen2-2 mutant background using a PEN2-like targeting strategy. The resulting lines were assessed by gene expression, protein accumulation, metabolite analysis and pathogen resistance assays. In parallel, targeted mutagenesis, structural comparison and phylogenetic analysis were used to examine molecular and evolutionary features of PEN2-related myrosinases. C_LIO_LIAtBGLU27 and BrBABG.a, but not AtBGLU18, AtBGLU23 or AtBGLU28, partially restored indole glucosinolate hydrolysis and resistance to Colletotrichum tropicale in pen2-2. Unlike AtPEN2, both enzymes acted mainly constitutively and showed distinct substrate preferences. PEN2, BGLU27 and BABG proteins lacked conserved post-translational modification sites, including residues associated with a conserved disulfide bond. Restoring this disulfide bond in AtPEN2 abolished its activity. C_LIO_LIPEN2-related myrosinases form an evolutionarily distinct BGLU lineage associated with indole glucosinolate metabolism in Brassicales. Loss of the conserved disulfide bond appears to be required for PEN2 activity, whereas additional PEN2-specific regulatory features are needed for pathogen-triggered, rather than constitutive, glucosinolate metabolism. C_LI

plant biology↗
bioRxiv2025

APOBEC3A deaminase catalyzes site-specific editing of transfer RNAs

APOBEC3A is a cytidine deaminase that plays a crucial role in innate immunity; however, it can also drive oncogenesis when dysregulated. While its DNA editing activity is well-studied, the impact of APOBEC3A on RNA has only recently gained attention. Previous studies revealed that APOBEC3A deaminates mRNA stem-loop structures, however, its activity on other RNA classes remains unexplored. Given its likely evolutionary origin from tRNA adenosine deaminases and the prevalence of stem-loop structures in tRNA, we investigated APOBEC3As activity on tRNAs. We found that in vitro APOBEC3A efficiently deaminates a large spectrum of tRNA isoacceptors, primarily at anticodon positions. To assess whether the editing sites identified in vitro can be detected in tumor tissues, we analyzed data from The Cancer Genome Atlas. We identified six editing sites present in numerous patient samples. Our results point to a possible impact of APOBEC3A on tRNA decoding capacity, with potential relevance to mistranslation and cancer development.

molecular biology↗