Histone variant H2B.Z acetylation is necessary for maintenance of Toxoplasma gondii biological fitness.

Through regulation of DNA packaging, histone proteins are fundamental to a wide array of biological processes. A variety of post-translational modifications (PTMs), including acetylation, constitute a proposed histone code that is interpreted by "reader" proteins to modulate chromatin structure. Canonical histones can be replaced with variant versions that add an additional layer of regulatory complexity.

Histone variant H2B.Z acetylation is necessary for maintenance of biological fitness.

Through regulation of DNA packaging, histone proteins are fundamental to a wide array of biological processes. A variety of post-translational modifications (PTMs), including acetylation, constitute a proposed histone code that is interpreted by "reader" proteins to modulate chromatin structure. Canonical histones can be replaced with variant versions that add an additional layer of regulatory complexity.

Structure of the class XI myosin globular tail reveals evolutionary hallmarks for cargo recognition in plants.

The plant-specific class XI myosins (MyoXIs) play key roles at the molecular, cellular and tissue levels, engaging diverse adaptor proteins to transport cargoes along actin filaments. To recognize their cargoes, MyoXIs have a C-terminal globular tail domain (GTD) that is evolutionarily related to those of class V myosins (MyoVs) from animals and fungi. Despite recent advances in understanding the functional roles played by MyoXI in plants, the structure of its GTD, and therefore the molecular determinants for cargo selectivity and recognition, remain elusive.

Exploring protein myristoylation in Toxoplasma gondii.

Toxoplasma gondii is an important human and veterinary pathogen and the causative agent of toxoplasmosis, a potentially severe disease especially in immunocompromised or congenitally infected humans. Current therapeutic compounds are not well-tolerated, present increasing resistance, limited efficacy and require long periods of treatment. On this context, searching for new therapeutic targets is crucial to drug discovery.

Altered levels of mitochondrial NFS1 affect cellular Fe and S contents in plants.

The ISC Fe-S cluster biosynthetic pathway would play a key role in the regulation of iron and sulfur homeostasis in plants. The Arabidopsis thaliana mitochondrial cysteine desulfurase AtNFS1 has an essential role in cellular ISC Fe-S cluster assembly, and this pathway is one of the main sinks for iron (Fe) and sulfur (S) in the plant. In different plant species it has been reported a close relationship between Fe and S metabolisms; however, the regulation of both nutrient homeostasis is not fully understood.

Palmitoylation in apicomplexan parasites: from established regulatory roles to putative new functions.

This minireview aims to provide a comprehensive synthesis on protein palmitoylation in apicomplexan parasites and higher eukaryotes where most of the data is available. Apicomplexan parasites encompass numerous obligate intracellular parasites with significant health risk to animals and humans. Protein palmitoylation is a widespread post-translational modification that plays important regulatory roles in several physiological and pathological states.

Effects of the linker region on the structure and function of modular GH5 cellulases.

The association of glycosyl hydrolases with catalytically inactive modules is a successful evolutionary strategy that is commonly used by biomass-degrading microorganisms to digest plant cell walls. The presence of accessory domains in these enzymes is associated with properties such as higher catalytic efficiency, extension of the catalytic interface and targeting of the enzyme to the proper substrate. However, the importance of the linker region in the synergistic action of the catalytic and accessory domains remains poorly understood.

Frataxin Is Localized to Both the Chloroplast and Mitochondrion and Is Involved in Chloroplast Fe-S Protein Function in Arabidopsis.

Frataxin plays a key role in eukaryotic cellular iron metabolism, particularly in mitochondrial heme and iron-sulfur (Fe-S) cluster biosynthesis. However, its precise role has yet to be elucidated. In this work, we studied the subcellular localization of Arabidopsis frataxin, AtFH, using confocal microscopy, and found a novel dual localization for this protein.

Structural and functional studies of the mitochondrial cysteine desulfurase from Arabidopsis thaliana.

AtNfs1 is the Arabidopsis thaliana mitochondrial homolog of the bacterial cysteine desulfurases NifS and IscS, having an essential role in cellular Fe-S cluster assembly. Homology modeling of AtNfs1m predicts a high global similarity with E. coli IscS showing a full conservation of residues involved in the catalytic site, whereas the chloroplastic AtNfs2 is more similar to the Synechocystis sp.

The mitochondrial protein frataxin is essential for heme biosynthesis in plants.

Frataxin, a conserved mitochondrial protein implicated in cellular iron homeostasis, has been involved as the iron chaperone that delivers iron for the Fe-S cluster and heme biosynthesis. However, its role in iron metabolism remains unclear, especially in photosynthetic organisms. In previous work, we found that frataxin deficiency in Arabidopsis results in decreased activity of the mitochondrial Fe-S proteins aconitase and succinate dehydrogenase, despite the increased expression of the respective genes, indicating an important role for Arabidopsis thaliana frataxin homolog (AtFH).

Effect of mitochondrial dysfunction on carbon metabolism and gene expression in flower tissues of Arabidopsis thaliana.

We characterized the transcriptomic response of transgenic plants carrying a mitochondrial dysfunction induced by the expression of the unedited form of the ATP synthase subunit 9. The u-ATP9 transgene driven by A9 and APETALA3 promoters induce mitochondrial dysfunction revealed by a decrease in both oxygen uptake and adenine nucleotides (ATP, ADP) levels without changes in the ATP/ADP ratio. Furthermore, we measured an increase in ROS accumulation and a decrease in glutathione and ascorbate levels with a concomitant oxidative stress response.