Biology subjects

Cortazar, A. R.

Publications and source records attributed to Cortazar, A. R..

3 recordsLinked to original sources

bioRxiv2020

Identification of proximal SUMO-dependent interactors using SUMO-ID

The fast dynamics and reversibility of posttranslational modifications by the ubiquitin family pose significant challenges for research. Here we present SUMO-ID, a technology that merges proximity biotinylation by TurboID and protein-fragment complementation to find SUMO-dependent interactors of proteins of interest. We developed an optimized split-TurboID version and show SUMO interaction-dependent labelling of proteins proximal to PML and RANGAP1. SUMO-dependent interactors of PML are involved in transcription, DNA damage, stress response and SUMO modification and are highly enriched in SUMO Interacting Motifs, but may only represent a subset of the total PML proximal proteome. Likewise, SUMO-ID also allowed us to identify novel interactors of SUMOylated SALL1, a less characterized SUMO substrate. Thus, SUMO-ID is a powerful tool that allows to study the consequences of SUMO-dependent interactions, and may further unravel the complexity of the ubiquitin code.

biochemistry↗

bioRxiv2020

USP29 is a novel non-canonical Hypoxia Inducible Factor-α activator

Hypoxia Inducible Factor (HIF) is the master transcriptional regulator that orchestrates cellular adaptation to low oxygen. HIF is tightly regulated via the stability of its -subunit, which is subjected to oxygen-dependent proline hydroxylation by Prolyl-Hydroxylase Domain containing proteins (PHDs/EGLNs), and ultimately targeted for proteasomal degradation through poly-ubiquitination by von-Hippel-Lindau protein (pVHL). However, sustained HIF- signalling is found in many tumours independently of oxygen availability pointing towards the relevance of non-canonical HIF- regulators. In this study, we establish the Ubiquitin Specific Protease 29 (USP29) as direct post-translational activator of HIF- in a variety of cancer cell lines. USP29 binds to HIF-, decreases poly-ubiquitination and thus protects HIF- from proteasomal degradation. Deubiquitinating activity of USP29 is essential to stabilise not only HIF-1 but also HIF-2, via their C-termini in an oxygen/PHD/pVHL-independent manner. Furthermore, in prostate cancer samples the expression of USP29 correlates with the HIF-target gene CA9 (carbonic anhydrase 9) as well as disease progression and severity.

cell biology↗

bioRxiv2018

Integrative analysis of transcriptomic and clinical data uncovers the tumor suppressive activity of MITF in prostate cancer.

The dysregulation of gene expression is an enabling hallmark of cancer. Computational analysis of transcriptomics data from human cancer specimens, complemented with exhaustive clinical annotation, provides an opportunity to identify core regulators of the tumorigenic process. Here we exploit well-annotated clinical datasets of prostate cancer for the discovery of transcriptional regulators relevant to prostate cancer. Following this rationale, we identify Microphthalmia-associated transcription factor (MITF) as a prostate tumor suppressor among a subset of transcription factors. Importantly, we further interrogate transcriptomics and clinical data to refine MITF perturbation-based empirical assays and unveil Crystallin Alpha B (CRYAB) as an unprecedented direct target of the transcription factor that is, at least in part, responsible for its tumor suppressive activity in prostate cancer. This evidence was supported by the enhanced prognostic potential of a signature based on the concomitant alteration of MITF and CRYAB in prostate cancer patients. In sum, our study provides proof-of-concept evidence of the potential of the bioinformatics screen of publicly available cancer patient databases as discovery platforms, and demonstrates that the MITF-CRYAB axis controls prostate cancer biology.

cancer biology↗