Biology subjects

Soares da Costa, T. P.

Publications and source records attributed to Soares da Costa, T. P..

5 recordsLinked to original sources

bioRxiv2022

A F420-dependent single domain chemogenetic tool for protein de-dimerization

Protein-protein interactions (PPIs) mediate many fundamental cellular processes and their control through optically or chemically responsive protein domains has a profound impact on basic research and some clinical applications. Most available chemogenetic methods induce the association, i.e., dimerization or oligomerization, of target proteins, and the few available dissociation approaches either break large oligomeric protein clusters or heteromeric complexes. Here, we have exploited the controlled dissociation of a dimeric oxidoreductase from mycobacteria (MSMEG_2027) by its native cofactor, F420, which is not present in mammals, as a bioorthogonal monomerization switch. We found that in the absence of F420, MSMEG_2027 forms a unique domain-swapped dimer that occludes the cofactor binding site. Substantial remodelling of the intertwined N-terminal helix upon F420 binding results in the dissolution of the dimer. We then show that MSMEG_2027 can be expressed as fusion proteins in human cells and apply it as a tool to induce and release MAPK/ERK signalling downstream of a chimeric fibroblast growth factor receptor 1 (FGFR1) tyrosine kinase. This F420-dependent chemogenetic de-dimerization tool is stoichiometric, based on a single domain and presents a novel mechanism to investigate protein complexes in situ.

synthetic biology↗

bioRxiv2022

A dual-target herbicidal inhibitor of lysine biosynthesis

Herbicides with novel modes of action are urgently needed to safeguard global agricultural industries against the damaging effects of herbicide-resistant weeds. We recently developed the first herbicidal inhibitors of lysine biosynthesis, which provided proof-of-concept for a promising novel herbicide target (Soares da Costa et al., 2021). In this study, we expanded upon our understanding of the mode of action of herbicidal lysine biosynthesis inhibitors. We previously postulated that these inhibitors may act as proherbicides (Soares da Costa et al., 2021). Here we show this is not the case. We report an additional mode of action of these inhibitors, through their inhibition of a second lysine biosynthesis enzyme, and investigate the molecular determinants of inhibition. Furthermore, we extend our herbicidal activity analyses to include a weed species of global significance.

biochemistry↗

bioRxiv2022

The First Inhibitor of Meso-Diaminopimelate Biosynthesis with Antibacterial Activity Against Multi-Drug Resistant Bacteria

Antibiotic resistance represents one of the biggest threats to global health. While several of our current antibiotics target the peptidoglycan within the bacterial cell wall, only a fraction of its components has been explored for antibiotic development. A component that remains under-exploited is meso-diaminopimelate (meso-DAP), a constituent of the cross-linking peptide in Gram-negative bacteria. In this study, we employed a high throughput chemical screen to identify the first inhibitor of meso-DAP biosynthesis with antibacterial activity. Indeed, the compound was shown to have minimum inhibitory concentration values of 8-16 g/mL against a panel of multi-drug resistant Acinetobacter baumannii strains, including those resistant to the last resort antibiotic carbapenem. Importantly, the compound targets the meso-DAP biosynthesis pathway specifically, with no off-target effects observed in human cell lines, and no resistance exhibited upon continuous treatment, under the conditions tested. Furthermore, we revealed for the first time that meso-DAP biosynthesis inhibition prevents biofilm formation and disrupts established biofilms in A. baumannii. Using a Galleria mellonella model, we showed that this compound improves survival rates against A. baumannii infection by up to 40% relative to the no treatment controls. Lastly, we determined that the inhibitor potentiates the activity of several antibiotic classes, including carbapenems. Thus, this study provides proof-of-concept that meso-DAP biosynthesis represents a promising target for the development of standalone antibacterial agents with a new mode of action as well as adjuvants to be used in combinatorial regimens to rejuvenate our current antibiotic arsenal to combat resistance. ImportanceResistance levels to available antibiotics continues to rise, with a growing number of Gram-negative bacterial infections, in particular A. baumannii infections, becoming life-threatening. Despite this, there have been no new classes of antibiotics against Gram-negative bacteria introduced to the market over the last 40 years. Hence, new targets and therapeutics are urgently required to combat these clinically important pathogens. One such target is meso-DAP, a critical component of the cross-linking peptides in the cell walls of Gram-negative bacteria. Here, we describe the first inhibitor of bacterial meso-DAP biosynthesis, with antibacterial activity against multi-drug resistant Gram-negative bacterial strains, including carbapenem-resistant A. baumannii. We also reveal that meso-DAP biosynthesis inhibition affects biofilm stability and potentiates the activity of several antibiotic classes. This study highlights the need to further explore meso-DAP biosynthesis and other unexploited targets in the search for antibiotics with new modes of action.

microbiology↗

bioRxiv2021

Towards Novel Herbicide Modes of Action by Inhibiting Lysine Biosynthesis in Plants

Weeds are becoming increasingly resistant to our current herbicides, posing a significant threat to agricultural production. Therefore, new herbicides are urgently needed. In this study, we exploited a novel herbicide target, dihydrodipicolinate synthase (DHDPS), which catalyses the first and rate-limiting step in lysine biosynthesis. Using a high throughput chemical screen, we identified the first class of plant DHDPS inhibitors that have micromolar potency against Arabidopsis thaliana DHDPS isoforms. Employing X-ray crystallography, we determined that this class of inhibitors binds to a novel and unexplored pocket within DHDPS, which is highly conserved across plant species. We also demonstrated that the inhibitors attenuated the germination and growth of A. thaliana seedlings and confirmed their pre-emergence herbicidal activity in soil-grown plants. These results provide proof-of-concept that lysine biosynthesis represents a promising target for the development of herbicides with a novel mode of action to tackle the global rise of herbicide resistant weeds.

biochemistry↗

bioRxiv2020

Structural insight into tanapoxvirus mediated inhibition of apoptosis

Premature programmed cell death or apoptosis of cells is a strategy utilized by multicellular organisms to counter microbial threats. Tanapoxvirus (TANV) is a large double-stranded DNA virus belonging to the poxviridae that causes mild Monkeypox-like infections in humans and primates. TANV encodes for a putative apoptosis inhibitory protein 16L. We show that TANV16L is able to bind to a range of peptides spanning the BH3 motif of human pro-apoptotic Bcl-2 proteins, and is able to counter growth arrest of yeast induced by human Bak and Bax. We then determined the crystal structures of TANV16L bound to three identified interactors, Bax, Bim and Puma BH3. TANV16L adopts a globular Bcl-2 fold comprising 7 -helices, and utilizes the canonical Bcl-2 binding groove to engage pro-apoptotic host cell Bcl-2 proteins. Unexpectedly, TANV16L is able to adopt both a monomeric as well as a domain-swapped dimeric topology where the 1 helix from one protomer is swapped into a neighbouring unit. Despite adopting two different oligomeric forms, the canonical ligand binding groove in TANV16L remains unchanged from monomer to domain-swapped dimer. Our results provide a structural and mechanistic basis for tanapoxvirus mediated inhibition of host cell apoptosis, and reveal the capacity of Bcl-2 proteins to adopt differential oligomeric states whilst maintaining the canonical ligand binding groove in an unchanged state.

microbiology↗