Biology subjects

Garcia-Dominguez, M.

Publications and source records attributed to Garcia-Dominguez, M..

4 recordsLinked to original sources

bioRxiv2024

Topological regulation of the estrogen transcriptional response by ZATT-mediated inhibition of TOP2B activity

Human type-II topoisomerases, TOP2A and TOP2B, remove transcription associated DNA supercoiling, thereby affecting gene-expression programs, and have recently been associated with 3D genome architecture. Here, we study the regulatory roles of TOP2 paralogs in response to estrogen, which triggers an acute transcriptional induction that involves rewiring of genome organization. We find that, whereas TOP2A facilitates transcription, as expected for a topoisomerase, TOP2B limits the estrogen response. Consistent with this, TOP2B activity is locally downregulated upon estrogen treatment to favor the establishment and stabilization of regulatory chromatin contacts, likely through an accumulation of DNA supercoiling. We show that estrogen-mediated inhibition of TOP2B requires estrogen receptor (ER), a non-catalytic function of TOP2A, and the action of the atypical SUMO-ligase ZATT. This mechanism of topological transcriptional-control, which may be shared by additional gene-expression circuits, highlights the relevance of DNA topoisomerases as central actors of genome dynamics.

molecular biology↗

bioRxiv2023

MAPK/MAK/MRK overlapping kinase (MOK) controls microglial inflammatory/type-I IFN responses via Brd4 and is involved in ALS pathophysiology

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease affecting motor neurons and characterized by microglia-mediated neurotoxic inflammation whose underlying mechanisms remain incompletely understood. In this work we reveal that MAPK/MAK/MRK overlapping kinase (MOK), with unknown physiological substrate, displays an immune function by controlling inflammatory and type-I IFN responses in microglia which are detrimental to primary motor neurons. Moreover, we uncover the epigenetic reader bromodomain-containing protein 4 (Brd4) as the first molecule regulated by MOK, by promoting Ser492-phospho-Brd4 levels. We further demonstrate that MOK regulates Brd4 functions by supporting its binding to cytokine gene promoters, therefore enabling innate immune responses. Remarkably, we show that MOK levels are increased in ALS spinal cord, particularly in microglial cells, and that administration of a chemical MOK-inhibitor to ALS model mice is able to modulate Ser492-phospho-Brd4 levels, suppress microglial activation and modify disease course, indicating a pathophysiological role of MOK kinase in ALS and neuroinflammation.

neuroscience↗

bioRxiv2020

Proteomic analysis reveals Utf1 as a neurogenesis-associated new Sumo target

Post-translational modification by covalent attachment of Sumo regulates numerous processes in vertebrates. Despite demonstrated roles of Sumo in development and function of the nervous system, the identification of key factors displaying a sumoylation-dependent activity during neurogenesis remains elusive. Based on SILAC, we have identified the Sumo proteome of proliferating and neuronal-differentiating cells. More than 300 putative Sumo targets differentially associated with one or the other condition. Among these, Utf1 revealed as a new Sumo target. Gain-of-function experiments demonstrated marked differences between the effects on neurogenesis of wild type and sumoylation mutant versions of selected proteins. While sumoylation of Prox1, Sall4a, Trim24 and Utf1 associated with a positive effect on neurogenesis, sumoylation of Kctd15 associated with a negative effect. Similar results were observed in embryos. Finally, detailed analysis of Utf1 showed sumoylation-dependent control of bivalent genes expression. This effect relies on two mechanisms: sumoylation modulates Utf1 chromatin binding and mediates recruitment of the mRNA-decapping enzyme Dcp1a through a conserved SIM. Altogether, our results indicate that combined sumoylation status of key proteins determine proper progress of neurogenesis. Sumo/transcription/chromatin/neurogenesis/Utf1

cell biology↗

bioRxiv2020

RanBP2-mediated SUMOylation promotes human DNA polymerase lambda nuclear localization and DNA repair

Cellular DNA is under constant attack by a wide variety of agents, both endogenous and exogenous. To counteract DNA damage, human cells have a large collection of DNA repair factors. Among them, DNA polymerase lambda (Pol{lambda}) stands out for its versatility, as it participates in different DNA repair and damage tolerance pathways in which gap-filling DNA synthesis is required. In this work we show that human Pol{lambda} is conjugated with Small Ubiquitin-like MOdifier (SUMO) proteins both in vitro and in vivo, with Lys27 being the main target of this covalent modification. Pol{lambda} SUMOylation takes place in the nuclear pore complex and is mediated by the E3 ligase RanBP2. This post-translational modification promotes Pol{lambda} entry into the nucleus, which is required for its recruitment to DNA lesions and stimulated by DNA damage induction. Our work represents an advance in the knowledge of molecular pathways that regulate cellular localization of human Pol{lambda}, which are essential to be able to perform its functions during repair of nuclear DNA, and that might constitute an important point for the modulation of its activity in human cells.

biochemistry↗