Biology subjects

Mariscal, J.

Publications and source records attributed to Mariscal, J..

3 recordsLinked to original sources

bioRxiv2024

Extracellular Vesicles heterogeneity through the lens of multiomics

Extracellular vesicles (EVs) are heterogenous in size, biogenesis, cargo and function. Beside small EVs, aggressive tumor cells release a population of particularly large EVs, namely large oncosomes (LO). This study provides the first resource of label-free quantitative proteomics of LO and small EVs obtained from distinct cancer cell types (prostate, breast, and glioma). This dataset was integrated with a SWATH Proteomic assay on LO, rigorously isolated from the plasma of patients with metastatic prostate cancer (PC). Proteins enriched in LO, which were identified also at the RNA level, and found in plasma LO significantly correlated with PC progression. Single EV RNA-Seq of the PC cell-derived LO confirmed some of the main findings from the bulk RNA-Seq, providing first evidence that single cell technologies can be successfully applied to EVs. This multiomics resource of cancer EVs can be leveraged for developing a multi-analyte approach for liquid biopsy.

cancer biology↗

bioRxiv2019

Comprehensive palmitoyl-proteomic analysis identifies distinct protein signatures for large and small cancer-derived extracellular vesicles

Extracellular vesicles (EVs) are membrane-enclosed particles that play an important role in cancer progression and have emerged as a promising source of circulating biomarkers. Protein S-acylation, also known as palmitoylation, has been proposed as a post-translational mechanism that modulates the dynamics of EV biogenesis and protein cargo sorting. However, technical challenges have limited large-scale profiling of the whole palmitoyl-proteins of EVs. We successfully employed a novel approach that combines low-background acyl-biotinyl exchange (LB-ABE) with label-free proteomics to analyze the palmitoyl proteome of large EVs (L-EVs) and small EVs (S-EVs) from prostate cancer cells. Here we report the first palmitoyl-protein signature of EVs, and demonstrate that L- and S-EVs harbor proteins associated with distinct biological processes and subcellular origin. We identified STEAP1, STEAP2, and ABBC4 as prostate cancer-specific palmitoyl proteins enriched in both EV populations in comparison with the originating cell lines. Importantly, the presence of the above proteins in EVs was significantly reduced upon inhibition of palmitoylation in the producing cells. These results suggest that palmitoylation may be involved in the differential sorting of proteins to distinct EV populations and allow for better detection of disease biomarkers.

cancer biology↗

bioRxiv2019

Low-background Acyl-biotinyl Exchange Largely Eliminates the Co-isolation of Non-S-acylated Proteins and Enables Deep S-acylproteomic Analysis

Protein S-acylation (also called palmitoylation) is a common post-translational modification whose deregulation plays a key role in the pathogenesis of many diseases. Acyl-biotinyl exchange (ABE), a widely used method for the enrichment of S-acylated proteins, has the potential of capturing the entire S-acylproteome in any types of biological samples. Here, we showed that current ABE methods suffer from high background arising from the co-isolation of non-S-acylated proteins. The background can be substantially reduced by an additional blockage of residual free cysteine residues with 2,2-dithiodipyridine prior to biotin-HPDP reaction. Coupling the low-background ABE (LB-ABE) method with label-free quantitative proteomics, 2,895 high-confidence candidate S-acylated proteins (including 1,591 known S-acylated proteins) were identified from human prostate cancer LNCaP cells, representing so-far the largest S-acylproteome dataset identified in a single study. Immunoblotting analysis confirmed the S-acylation of five known and five novel prostate cancer-related S-acylated proteins in LNCaP cells and suggested that their S-acylation levels were about 0.6-1.8%. In summary, the LB-ABE method largely eliminates the co-isolation of non-S-acylated proteins and enables deep S-acylproteomic analysis. It is expected to facilitate much more comprehensive and accurate quantification of S-acylproteomes than previous ABE methods.

biochemistry↗