Biology subjects

Haskard, D. O.

Publications and source records attributed to Haskard, D. O..

3 recordsLinked to original sources

bioRxiv2023

Chemical Tools for Profiling the Intracellular ADP-ribosylated Proteome

The post-translational modification (PTM) ADP-ribosylation plays an important role in cell signaling and regulating protein function and has been implicated in the development of multiple diseases, including breast and ovarian cancers. Studying the underlying mechanisms through which this PTM contributes towards disease development, however, has been hampered by the lack of appropriate tools for reliable identification of physiologically relevant ADP-ribosylated proteins in a live-cell environment. Herein, we explore the applications of an alkyne-tagged proprobe, 6Yn-ProTide-Ad (6Yn-Pro) as a chemical tool for the identification of intracellular ADP-ribosylated proteins through metabolic labelling. We applied targeted metabolomics and chemical proteomics in HEK293T cells treated with 6Yn-Pro to demonstrate intracellular metabolic conversion of the probe into ADP-ribosylation cofactor 6Yn-NAD+, and subsequent labelling and enrichment of PARP1 and multiple known ADP-ribosylated proteins in cells under hydrogen peroxide-induced stress. We anticipate that the approach and methodology described here will be useful for future identification of novel intracellular ADP-ribosylated proteins. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/555609v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@d50b3aorg.highwire.dtl.DTLVardef@d43023org.highwire.dtl.DTLVardef@a48ae2org.highwire.dtl.DTLVardef@9a0a1e_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

bioRxiv2023

Cytokine-Mediated Degradation of the Transcription Factor ERG Impacts the Pulmonary Vascular Response to Systemic Inflammatory Challenge

BackgroundDuring infectious diseases, pro-inflammatory cytokines transiently destabilize interactions between adjacent vascular endothelial cells (ECs) to facilitate the passage of immune molecules and cells into tissues. However, in the lung the resulting vascular hyperpermeability can lead to organ dysfunction. Previous work identified the transcription factor ERG as a master regulator of endothelial homeostasis. Here we investigate whether the sensitivity of pulmonary blood vessels to cytokine-induced destabilization is due to organotypic mechanisms affecting the ability of endothelial ERG to protect lung ECs from inflammatory injury. MethodsCytokine-dependent ubiquitination and proteasomal degradation of ERG was analyzed in cultured Human Umbilical Vein ECs (HUVECs). Systemic administration of TNF or the bacterial cell wall component lipopolysaccharide (LPS) was used to cause a widespread inflammatory challenge in mice; ERG protein levels were assessed by immunoprecipitation, immunoblot, and immunofluorescence. Murine Erg deletion was genetically induced in ECs (Ergfl/fl;Cdh5(PAC)CreERT2), and multiple organs were analyzed by histology, immunostaining, and electron microscopy. ResultsIn vitro, TNF promoted the ubiquitination and degradation of ERG in HUVECs, which was blocked by the proteasomal inhibitor MG132. In vivo, systemic administration of TNF or LPS resulted in a rapid and substantial degradation of ERG within lung ECs, but not ECs of the retina, heart, liver, or kidney. Pulmonary ERG was also downregulated in a murine model of influenza infection. Ergfl/fl;Cdh5(PAC)-CreERT2 mice spontaneously recapitulated aspects of inflammatory challenges, including lung-predominant vascular hyperpermeability, immune cell recruitment, and fibrosis. These phenotypes were associated with a lung-specific decrease in the expression of Tek, a gene target of ERG previously implicated in maintaining pulmonary vascular stability during inflammation. ConclusionsCollectively, our data highlight a unique role for ERG in pulmonary vascular function. We propose that cytokine-induced ERG degradation and subsequent transcriptional changes in lung ECs play critical roles in the destabilization of pulmonary blood vessels during infectious diseases.

cell biology↗

bioRxiv2019

An Integrated Chemical Proteomics Approach for Quantitative Profiling of Intracellular ADP-Ribosylation

ADP-ribosylation is integral to a diverse range of cellular processes such as DNA repair, chromatin regulation and RNA processing. However, proteome-wide investigation of its cellular functions has been limited due to numerous technical challenges including the complexity of the poly(ADP-ribose) (PAR) chains, low abundance of the modification and lack of sensitive enrichment methods. To facilitate live-cell profiling of ADP-ribosylated proteins, we show that 2-alkyne-adenosine (2YnAd) is metabolically incorporated in mammalian cells and enables fluorescent detection and robust affinity enrichment of the modified proteins. We then present an integrated chemical biology approach that involves simultaneous metabolic incorporation of 2YnAd and the previously reported 6-alkyne-adenosine (6YnAd) in live cells followed by click chemistry with a capture reagent to facilitate highly sensitive and comprehensive enrichment of the modified proteins. By combining this dual metabolic labelling strategy with the tandem mass tag (TMT) isobaric mass spectrometry, we have quantified the responses of thousands of endogenous proteins to clinical PARP inhibitors Olaparib and Rucaparib. Our study provides insight into the wider scope of PARP targets and will help to advance further characterisation of their functional roles.

biochemistry↗