Publications by authors named "Alejandro D Nadra"

Background: Plasticity in sensory perception and tolerance to xenobiotics contributes to insects' adaptive capacity and evolutionary success, by enabling them to cope with potentially toxic molecules from the environment or internal milieu. Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) have traditionally been studied in the context of chemoreception. However, accumulating evidence over the past few years indicates that these protein families can also sequester insecticide molecules.

View Article and Find Full Text PDF

During the COVID-19 outbreak, numerous tools including protein-based vaccines have been developed. The methylotrophic yeast Pichia pastoris (synonymous to Komagataella phaffii) is an eukaryotic cost-effective and scalable system for recombinant protein production, with the advantages of an efficient secretion system and the protein folding assistance of the secretory pathway of eukaryotic cells. In a previous work, we compared the expression of SARS-CoV-2 Spike Receptor Binding Domain in P.

View Article and Find Full Text PDF

Cyanotoxins produced during harmful algal blooms (CyanoHABs) have become a worldwide issue of concern. Microcystins (MC) are the most ubiquitous group of cyanotoxins and have known carcinogenic and hepatotoxic effects. The protein phosphatase inhibition assays (PPIAs), based on the inhibition of Protein Phosphatase 1/2A (PP1/PP2A) by MC, are one of the most cost-effective options for detecting MC.

View Article and Find Full Text PDF

Plant genomes encode a unique group of papain-type Cysteine EndoPeptidases (CysEPs) containing a KDEL endoplasmic reticulum (ER) retention signal (KDEL-CysEPs or CEPs). CEPs process the cell-wall scaffolding EXTENSIN (EXT) proteins that regulate de novo cell-wall formation and cell expansion. Since CEPs cleave EXTs and EXT-related proteins, acting as cell-wall-weakening agents, they may play a role in cell elongation.

View Article and Find Full Text PDF

Root hair cells are important sensors of soil conditions. They grow towards and absorb water-soluble nutrients. This fast and oscillatory growth is mediated by continuous remodeling of the cell wall.

View Article and Find Full Text PDF

Root Hairs (RHs) growth is influenced by endogenous and by external environmental signals that coordinately regulate its final cell size. We have recently determined that RH growth was unexpectedly boosted when Arabidopsis thaliana seedlings are cultivated at low temperatures. It was proposed that RH growth plasticity in response to low temperature was linked to a reduced nutrient availability in the media.

View Article and Find Full Text PDF

We study the limits imposed by transcription factor specificity on the maximum number of binding motifs that can coexist in a gene regulatory network, using the SwissRegulon Fantom5 collection of 684 human transcription factor binding sites as a model. We describe transcription factor specificity using regular expressions and find that most human transcription factor binding site motifs are separated in sequence space by one to three motif-discriminating positions. We apply theorems based on the pigeonhole principle to calculate the maximum number of transcription factors that can coexist given this degree of specificity, which is in the order of ten thousand and would fully utilize the space of DNA subsequences.

View Article and Find Full Text PDF
Article Synopsis
  • Aedes aegypti, a mosquito that transmits serious diseases, has developed resistance to synthetic insecticides, making alternative control methods necessary.
  • This study uses RNA-Seq to analyze gene expression in Aedes aegypti larvae after exposure to Eucalyptus camaldulensis essential oil, revealing genes related to detoxification and chemosensory responses.
  • The findings highlight the potential of Eucalyptus-derived compounds in mosquito control by identifying gene families involved in detoxification, which could enhance the effectiveness of natural larvicides in managing mosquito populations.
View Article and Find Full Text PDF

NKX2-5 is a homeodomain transcription factor that plays a crucial role in heart development. It is the first gene where a single genetic variant (GV) was found to be associated with congenital heart diseases in humans. In this study, we carried out a comprehensive survey of NKX2-5 GVs to build a unified, curated, and updated compilation of all available GVs.

View Article and Find Full Text PDF

Synthetic biology emerged in the USA and Europe twenty years ago and quickly developed innovative research and technology as a result of continued funding. Synthetic biology is also growing in many developing countries of Africa, Asia and Latin America, where it could have a large economic impact by helping its use of genetic biodiversity in order to boost existing industries. Starting in 2011, Argentine synthetic biology developed along an idiosyncratic path.

View Article and Find Full Text PDF

Mammalian frataxin is a small mitochondrial protein involved in iron sulfur cluster assembly. Frataxin deficiency causes the neurodegenerative disease Friedreich's Ataxia. Valuable knowledge has been gained on the structural dynamics of frataxin, metal-ion-protein interactions, as well as on the effect of mutations on protein conformation, stability and internal motions.

View Article and Find Full Text PDF

Engineering oligomeric protein self-assembly is an attractive approach to fabricate nanostructures with well-defined geometries, stoichiometry and functions. The homodecamer Lumazine Synthase (BLS) is a highly stable and immunogenic protein nanoparticle (PNP). Here, we engineered the BLS protein scaffold to display two functions in spatially opposite regions of its structure yielding a Janus-like nanoparticle.

View Article and Find Full Text PDF

Proteins are sensitive to temperature, and abrupt changes in the normal temperature conditions can have a profound impact on both structure and function, leading to protein unfolding. However, the adaptation of certain organisms to extreme conditions raises questions about the structural features that permit the structure and function of proteins to be preserved under these adverse conditions. To gain insight into the molecular basis of protein thermostability in the globin family, we have examined three representative examples: human neuroglobin, horse heart myoglobin, and Drosophila hemoglobin, which differ in their melting temperatures and coordination states of the heme iron in the absence of external ligands.

View Article and Find Full Text PDF

The subtle mechanisms by which protein-DNA interactions remain functional across a wide range of temperatures are largely unknown. In this work, we manually curated available information relating fully sequenced archaeal genomes with organism growth temperatures. We built a motif that represents the core promoter of each species and calculated its information content.

View Article and Find Full Text PDF

The diversity and flexibility of life offers a wide variety of molecules and systems useful for biosensing. A biosensor device should be robust, specific and reliable. Inorganic arsenic is a highly toxic water contaminant with worldwide distribution that poses a threat to public health.

View Article and Find Full Text PDF
Article Synopsis
  • Over 95% of CAH cases are related to steroid 21-hydroxylation issues, which range in severity from classical forms to mild late-onset types.
  • The researchers collected 1,340 genetic variants of the CYP21A2 gene, identifying 899 unique variants, 230 of which impact health, and created a database to aid in genetic counseling for affected families.
View Article and Find Full Text PDF

Root hair polar growth is endogenously controlled by auxin and sustained by oscillating levels of reactive oxygen species (ROS). These cells extend several hundred-fold their original size toward signals important for plant survival. Although their final cell size is of fundamental importance, the molecular mechanisms that control it remain largely unknown.

View Article and Find Full Text PDF
Article Synopsis
  • Congenital adrenal hyperplasia (CAH) is mainly caused by 21-hydroxylase deficiency, with the CYP21A2 gene mutations accounting for 90-95% of cases.
  • Researchers analyzed 343 mutations and SNPs in the CYP21A2 gene to determine their functional impacts, focusing on those that affect protein stability and comparing predictions with patient data.
  • The study identified five new mutations that may have a pathogenic effect and assessed the potential for compounded effects when multiple mutations occur together.
View Article and Find Full Text PDF

Background: Myoglobin (Mb) and neuroglobin (Ngb) are representative members of pentacoordinated and bis-histidyl, hexacoordinated globins. In spite of their low sequence identity, they show surprisingly similar three-dimensional folds. The ability of Ngb to form a hexacoordinated bis-histidyl complex with the distal HisE7 has a strong impact on ligand affinity.

View Article and Find Full Text PDF

PKA (cAMP-dependent protein kinase) activity, as well as that of other AGC members, is regulated by multiple phosphorylations of its catalytic subunits. In Saccharomyces cerevisiae, the PKA regulatory subunit is encoded by the gene BCY1, and the catalytic subunits are encoded by three genes: TPK1, TPK2 and TPK3. Previously, we have reported that, following cAMP/PKA pathway activation, Tpk1 increases its phosphorylation status.

View Article and Find Full Text PDF

Background: Understanding the molecular mechanism through which proteins are functional at extreme high and low temperatures is one of the key issues in structural biology. To investigate this phenomenon, we have focused on two instructive truncated hemoglobins from Thermobifida fusca (Tf-trHbO) and Mycobacterium tuberculosis (Mt-trHbO); although the two proteins are structurally nearly identical, only the former is stable at high temperatures.

Methods: We used molecular dynamics simulations at different temperatures as well as thermal melting profile measurements of both wild type proteins and two mutants designed to interchange the amino acid residue, either Pro or Gly, at E3 position.

View Article and Find Full Text PDF

Living organisms use biological clocks to maintain their internal temporal order and anticipate daily environmental changes. In Drosophila, circadian regulation of locomotor behavior is controlled by ∼150 neurons; among them, neurons expressing the PIGMENT DISPERSING FACTOR (PDF) set the period of locomotor behavior under free-running conditions. To date, it remains unclear how individual circadian clusters integrate their activity to assemble a distinctive behavioral output.

View Article and Find Full Text PDF
Article Synopsis
  • The Antarctic icefish Chaenocephalus aceratus, which lacks hemoglobin and myoglobin, has retained neuroglobin in its brain, showcasing unique structural properties compared to human neuroglobin and that of a related species.
  • Detailed analyses using spectroscopies and simulations revealed that these neuroglobins can bind oxygen and carbon monoxide, highlighting a significant structural cavity for potential ligand interactions.
  • While the Antarctic fish neuroglobins exhibit some modifications, their adaptations do not match the extensive changes seen in the oxygen-carrying globins of the same species.
View Article and Find Full Text PDF

Root hairs are single cells that develop by tip growth and are specialized in the absorption of nutrients. Their cell walls are composed of polysaccharides and hydroxyproline-rich glycoproteins (HRGPs) that include extensins (EXTs) and arabinogalactan-proteins (AGPs). Proline hydroxylation, an early posttranslational modification of HRGPs that is catalyzed by prolyl 4-hydroxylases (P4Hs), defines the subsequent O-glycosylation sites in EXTs (which are mainly arabinosylated) and AGPs (which are mainly arabinogalactosylated).

View Article and Find Full Text PDF

Synopsis of recent research by authors named "Alejandro D Nadra"

  • - Alejandro D Nadra's recent research focuses on innovative biosensor technologies, particularly in detecting environmental toxins and enhancing diagnostics and therapies for infectious diseases like COVID-19, utilizing cost-effective recombinant protein systems.
  • - His work includes investigating plant molecular biology, specifically how transcription factors and peroxidases control root hair growth, potentially influencing agricultural resilience and adaptation to environmental stressors.
  • - Nadra's studies also bridge the fields of genetics and synthetic biology, exploring genetic variants related to heart development and the establishment of synthetic biology communities in Argentina, aimed at promoting economic growth through genetic diversity exploitation.