Publications by authors named "Albert Galera-Prat"

ADP-ribosyltransferases PARP1 and PARP2 play a major role in DNA repair mechanism by detecting the DNA damage and inducing poly-ADP-ribosylation dependent chromatin relaxation and recruitment of repair proteins. Catalytic PARP inhibitors are used as anticancer drugs especially in the case of tumors arising from sensitizing mutations. Recently, a study showed that Histone PARylation Factor (HPF1) forms a joint active site with PARP1/2.

View Article and Find Full Text PDF

De novo design has been a hotly pursued topic for many years. Most recent developments have involved the use of deep learning methods for generative molecular design. Despite increasing levels of algorithmic sophistication, the design of molecules that are synthetically accessible remains a major challenge.

View Article and Find Full Text PDF

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has made it clear that further development of antiviral therapies will be needed to combat additional SARS-CoV-2 variants or novel CoVs. Here, we describe small molecule inhibitors for SARS-CoV-2 Mac1, which counters ADP-ribosylation mediated innate immune responses. The compounds inhibiting Mac1 were discovered through high-throughput screening (HTS) using a protein FRET-based competition assay and the best hit compound had an IC of 14 μM.

View Article and Find Full Text PDF

Unlabelled: The catalytic enzymes tankyrase 1 and 2 (TNKS1/2) alter protein turnover by poly-ADP-ribosylating target proteins, which earmark them for degradation by the ubiquitin-proteasomal system. Prominent targets of the catalytic activity of TNKS1/2 include AXIN proteins, resulting in TNKS1/2 being attractive biotargets for addressing of oncogenic WNT/β-catenin signaling. Although several potent small molecules have been developed to inhibit TNKS1/2, there are currently no TNKS1/2 inhibitors available in clinical practice.

View Article and Find Full Text PDF

We report [1,2,4]triazolo[3,4-]benzothiazole (TBT) as a new inhibitor scaffold, which competes with nicotinamide in the binding pocket of human poly- and mono-ADP-ribosylating enzymes. The binding mode was studied through analogues and cocrystal structures with TNKS2, PARP2, PARP14, and PARP15. Based on the substitution pattern, we were able to identify 3-amino derivatives (OUL243) and (OUL232) as inhibitors of mono-ARTs PARP7, PARP10, PARP11, PARP12, PARP14, and PARP15 at nM potencies, with being the most potent PARP10 inhibitor described to date (IC of 7.

View Article and Find Full Text PDF

Tankyrases are poly-ADP-ribosyltransferases that regulate many crucial and diverse cellular processes in humans such as Wnt signaling, telomere homeostasis, mitotic spindle formation and glucose metabolism. While tankyrases are present in most animals, functional differences across species may exist. In this work, we confirm the widespread distribution of tankyrases throughout the branches of multicellular animal life and identify the single-celled choanoflagellates as earliest origin of tankyrases.

View Article and Find Full Text PDF

Human mono-ADP-ribosylating PARP enzymes have been linked to several clinically relevant processes and many of these PARPs have been suggested as potential drug targets. Despite recent advances in the field, efforts to discover inhibitors have been hindered by the lack of tools to rapidly screen for high potency compounds and profile them against the different enzymes. We engineered mono-ART catalytic fragments to be incorporated into a cellulosome-based octavalent scaffold.

View Article and Find Full Text PDF

While human poly-ADP-ribose chain generating poly-ARTs, PARP1 and 2 and TNKS1 and 2, have been widely characterized, less is known on the pathophysiological roles of the mono-ADP-ribosylating mono-ARTs, partly due to the lack of selective inhibitors. In this context, we have focused on the development of inhibitors for the mono-ART PARP10, whose overexpression is known to induce cell death. Starting from OUL35 (1) and its 4-(benzyloxy)benzamidic derivative (2) we herein report the design and synthesis of new analogues from which the cyclobutyl derivative 3c rescued cells most efficiently from PARP10 induced apoptosis.

View Article and Find Full Text PDF

Here, we describe a protocol to set up a screening assay for ADP-ribosyl binding proteins including proteins that possess O-glycosidase or N-glycosidase activities. The FRET-based assay measures the interaction of any ADP-ribosyl binding protein fused to CFP with a cysteine-ADP-ribosylated GAP-tag fused to YFP. Recombinant PtxS1 and PARP2 are used to mono-ADP-ribosylate and poly-ADP-ribosylate the GAP-tag.

View Article and Find Full Text PDF

Tankyrase 1 and 2 (TNKS1/2) catalyze post-translational modification by poly-ADP-ribosylation of a plethora of target proteins. In this function, TNKS1/2 also impact the WNT/β-catenin and Hippo signaling pathways that are involved in numerous human disease conditions including cancer. Targeting TNKS1/2 with small-molecule inhibitors shows promising potential to modulate the involved pathways, thereby potentiating disease intervention.

View Article and Find Full Text PDF

The scaffold of TIQ-A, a previously known inhibitor of human poly-ADP-ribosyltransferase PARP1, was utilized to develop inhibitors against human mono-ADP-ribosyltransferases through structure-guided design and activity profiling. By supplementing the TIQ-A scaffold with small structural changes, based on a PARP10 inhibitor OUL35, selectivity changed from poly-ADP-ribosyltransferases towards mono-ADP-ribosyltransferases. Binding modes of analogs were experimentally verified by determining complex crystal structures with mono-ADP-ribosyltransferase PARP15 and with poly-ADP-ribosyltransferase TNKS2.

View Article and Find Full Text PDF

Proteins interacting with ADP-ribosyl groups are often involved in disease-related pathways or viral infections, making them attractive drug targets. We present a robust and accessible assay applicable to both hydrolyzing or non-hydrolyzing binders of mono- and poly-ADP-ribosyl groups. This technology relies on a C-terminal tag based on a G protein alpha subunit peptide (GAP), which allows for site-specific introduction of cysteine-linked mono- and poly-ADP-ribosyl groups or analogs.

View Article and Find Full Text PDF

Intracellular ADP-ribosyltransferases catalyze mono- and poly-ADP-ribosylation and affect a broad range of biological processes. The mono-ADP-ribosyltransferase PARP10 is involved in signaling and DNA repair. Previous studies identified OUL35 as a selective, cell permeable inhibitor of PARP10.

View Article and Find Full Text PDF

Human PARP2/ARTD2 is an ADP-ribosyltransferase which, when activated by 5'-phosphorylated DNA ends, catalyses poly-ADP-ribosylation of itself, other proteins and DNA. In this study, a crystal structure of PARP2 in complex with an activating 5'-phosphorylated DNA shows that the WGR domain bridges the dsDNA gap and joins the DNA ends. This DNA binding results in major conformational changes, including reorganization of helical fragments, in the PARP2 regulatory domain.

View Article and Find Full Text PDF
Article Synopsis
  • Amyloids are stable protein aggregates with a specific structure, and while they are usually linked to diseases, some functional amyloids play important roles in various organisms, including humans.
  • The CPEB protein, which helps regulate mRNA translation, shows aggregation patterns that might relate to memory processes, but the pathways of aggregation are not well understood among different species.
  • This research reveals that while the assembly pathways for CPEB proteins from different species (Aplysia and Drosophila) share late-stage similarities, they have distinct initial structural forms that influence how they begin to aggregate into amyloid-like structures.
View Article and Find Full Text PDF

Cellulose is the most abundant organic molecule on Earth and represents a renewable and practically everlasting feedstock for the production of biofuels and chemicals. Self-assembled owing to the high-affinity cohesin-dockerin interaction, cellulosomes are huge multi-enzyme complexes with unmatched efficiency in the degradation of recalcitrant lignocellulosic substrates. The recruitment of diverse dockerin-borne enzymes into a multicohesin protein scaffold dictates the three-dimensional layout of the complex, and interestingly two alternative binding modes have been proposed.

View Article and Find Full Text PDF

Tankyrases catalyse poly-ADP-ribosylation of their binding partners and the modification serves as a signal for the subsequent proteasomal degradation of these proteins. Tankyrases thereby regulate the turnover of many proteins involved in multiple and diverse cellular processes, such as mitotic spindle formation, telomere homeostasis and Wnt/β-catenin signalling. In recent years, tankyrases have become attractive targets for the development of inhibitors as potential therapeutics against cancer and fibrosis.

View Article and Find Full Text PDF

ADP-ribosylation is a post-translational modification involved in the regulation of many vital cellular processes. This posttranslational modification is carried out by ADP-ribosyltransferases converting β-NAD into nicotinamide and a protein-linked ADP-ribosyl group or a chain of PAR. The reverse reaction, release of ADP-ribose from the acceptor molecule, is catalyzed by ADP-ribosylhydrolases.

View Article and Find Full Text PDF

Tankyrases 1 and 2 are central biotargets in the WNT/β-catenin signaling and Hippo signaling pathways. We have previously developed tankyrase inhibitors bearing a 1,2,4-triazole moiety and binding predominantly to the adenosine binding site of the tankyrase catalytic domain. Here we describe a systematic structure-guided lead optimization approach of these tankyrase inhibitors.

View Article and Find Full Text PDF

Lignocellulose is the most abundant renewable carbon source in the biosphere. However, the main bottleneck in its conversion to produce second generation biofuels is the saccharification step: the hydrolysis of lignocellulosic material into soluble fermentable sugars. Some anaerobic bacteria have developed an extracellular multi-enzyme complex called the cellulosome that efficiently degrades cellulosic substrates.

View Article and Find Full Text PDF

Hearing and balance rely on the transduction of mechanical stimuli arising from sound waves or head movements into electrochemical signals. This archetypal mechanoelectrical transduction process occurs in the hair-cell stereocilia of the inner ear, which experience continuous oscillations driven by undulations in the endolymph in which they are immersed. The filamentous structures called tip links, formed by an intertwined thread composed of an heterotypic complex of cadherin 23 and protocadherin 15 ectodomain dimers, connect each stereocilium to the tip of the lower sterocilium, and must maintain their integrity against continuous stimulatory deflections.

View Article and Find Full Text PDF

Intrinsically disordered proteins (IDPs) lack a tertiary structure. Amyloidogenic IDPs (aIDPs) in particular have attracted great interest due to their implication in several devastating diseases as well as in critical biological functions. However, the conformational changes that trigger amyloid formation in aIDPs are largely unknown.

View Article and Find Full Text PDF

Cellulosomes are bacterial protein complexes that bind and efficiently degrade lignocellulosic substrates. These are formed by multimodular scaffolding proteins known as scaffoldins, which comprise cohesin modules capable of binding dockerin-bearing enzymes and usually a carbohydrate-binding module that anchors the system to a substrate. It has been suggested that cellulosomes bound to the bacterial cell surface might be exposed to significant mechanical forces.

View Article and Find Full Text PDF

Bacterial cellulases are drawing increased attention as a means to obtain plentiful chemical feedstocks and fuels from renewable lignocellulosic biomass sources. Certain bacteria deploy a large extracellular multi-protein complex, called the cellulosome, to degrade cellulose. Scaffoldin, a key non-catalytic cellulosome component, is a large protein containing a cellulose-specific carbohydrate-binding module and several cohesin modules which bind and organize the hydrolytic enzymes.

View Article and Find Full Text PDF