Biology subjects

Rodriguez, M. G.

Publications and source records attributed to Rodriguez, M. G..

3 recordsLinked to original sources

bioRxiv2026

A specialized SUV3 RNA helicase is involved in plant mitochondrial DNA repair

Synonymous substitution rates in the coding regions of land plant mitochondrial genomes are substantially lower than those in the nucleus. In contrast, non-coding regions are difficult or impossible to align except among very closely related species, suggesting that point mutation rates in these regions are considerably higher. Rearrangement breakpoints occur frequently within non-coding DNA, generating duplications, deletions, and inversions. To reconcile these contradictory patterns of genome evolution, it has been proposed that DNA damage is converted into double-strand breaks that are repaired through a combination of template-directed mechanisms and non-homologous end joining, while purifying selection preserves the integrity of coding sequences. Here we characterized AtSUV3, a mitochondrially targeted RNA helicase encoded by Arabidopsis thaliana At4g14790, a gene previously proposed to function as part of the plant mitochondrial degradosome. Mutations in AtSUV3 confer hypersensitivity to ciprofloxacin-induced mitochondrial DNA damage, CRISPR- knockout lines display increased ectopic recombination in the mitochondrial genome, and recombinant AtSUV3 exhibits ATP-dependent RNA helicase activity with a preference for 3'-ended substrates. Together, these findings identify AtSUV3 as a factor involved in mitochondrial dsDNA break repair. Consistent with our results, Arabidopsis and other plants encode an uncharacterized gene, AT5G39840.1, with 75% amino acid similarity with AtSUV3, dubbed herein as SUV3-like. We hypothesize that the AtSUV3 paralog has undergone specialization towards DNA repair, whereas AtSUV3-like protein may play a role in the plant organellar degradosome. Collectively, these findings identify AtSUV3 as a previously unrecognized factor involved in mitochondrial dsDNA break repair and provide a framework for understanding the diversification of DNA repair proteins during plant evolution.

plant biology↗

bioRxiv2024

Protein interaction map of APOBEC3 enzyme family reveals deamination-independent role in cellular function

Human APOBEC3 enzymes are a family of single-stranded (ss)DNA and RNA cytidine deaminases that act as part of the intrinsic immunity against viruses and retroelements. These enzymes deaminate cytosine to form uracil which can functionally inactivate or cause degradation of viral or retroelement genomes. In addition, APOBEC3s have deamination independent antiviral activity through protein and nucleic acid interactions. If expression levels are misregulated, some APOBEC3 enzymes can access the human genome leading to deamination and mutagenesis, contributing to cancer initiation and evolution. While APOBEC3 enzymes are known to interact with large ribonucleoprotein complexes, the function and RNA dependence is not entirely understood. To further understand their cellular roles, we determined by affinity purification mass spectrometry (AP-MS) the protein interaction network for the human APOBEC3 enzymes and map a diverse set of protein-protein and protein-RNA mediated interactions. Our analysis identified novel RNA-mediated interactions between APOBEC3C, APOBEC3H Haplotype I and II, and APOBEC3G with spliceosome proteins, and APOBEC3G and APOBEC3H Haplotype I with proteins involved in tRNA methylation and ncRNA export from the nucleus. In addition, we identified RNA-independent protein-protein interactions with APOBEC3B, APOBEC3D, and APOBEC3F and the prefoldin family of protein folding chaperones. Interaction between prefoldin 5 (PFD5) and APOBEC3B disrupted the ability of PFD5 to induce degradation of the oncogene cMyc, implicating the APOBEC3B protein interaction network in cancer. Altogether, the results uncover novel functions and interactions of the APOBEC3 family and suggest they may have fundamental roles in cellular RNA biology, their protein-protein interactions are not redundant, and there are protein-protein interactions with tumor suppressors, suggesting a role in cancer biology.

biochemistry↗

bioRxiv2019

Different salicylic and jasmonic acids imbalances are involved in the oxidative stress-mediated cell death, induced by fumonisin B1 in maize seedlings with contrasting resistance to Fusarium verticillioides ear rot in the field.

Background and aimFungal and plant secondary metabolites modulate the plant-pathogen interactions. However, the participation of fumonisins in the Fusarium verticillioides-maize pathosystem is unclear. In this work was studied the cell death, and the reactive oxygen species (ROS) - phytohormone imbalance interplay underlying the phytotoxicity of fumonisin B1 (FB1) in maize germplasms with contrasting resistance to Fusarium ear rot in the field. MethodsResistant (RH) and susceptible hybrid (SH) maize seedlings, grown from uninoculated seeds irrigated with FB1 (1 and 20 ppm), were harvested at 7, 14 and 21 days after planting, and were examined for electrolyte leakage (aerial parts); and for oxidative stress biomarkers (aerial parts and roots). The phytohormone (salicylic and jasmonic acids) imbalance interplay underlying the FB1-induced cell death were further explored in seedlings exposed 24 h to the mycotoxin (1 ppm) in hydroponics. ResultsCell death increased in RH and SH watered with 1 and 20 ppm of mycotoxin, respectively. Both toxin concentrations were pro-oxidant, and the major perturbations were found in roots. An Integrated Biomarker Response index was calculated suggesting that phytotoxicity occurs in a redox context more efficiently controlled by RH. ConclusionThe pre-treatment with the antioxidant ascorbic acid led to the conclusion that cell death in RH was related to a salicylic acid increase mediated by ROS. Nevertheless, FB1 induced two different phytohormonal regulatory mechanisms mediated by oxidative stress in both maize hybrids.

plant biology↗