Biology subjects

Masson, V.

Publications and source records attributed to Masson, V..

3 recordsLinked to original sources

bioRxiv2025

CARM1-mediated methylation controls interactions of ALIX with key partners important for cytokinesis

CARM1 is an arginine methyltransferase with a well-established role in regulating gene expression, but its cytoplasmic functions remain largely uncharacterized. Here, we identified ALIX, a protein acting with the ESCRT-III machinery in numerous membrane remodeling events, as a main cytoplasmic partner and a relevant substrate of CARM1. We demonstrate that CARM1 methylates arginine residues within the proline-rich motif of ALIX. At the molecular level, ALIX methylation impairs SH3-dependent association with CD2AP, CIN85, and endophilin-A2 that are required for cytokinesis. Using a mutant of ALIX that is unable to bind these proteins, we further show that these interactions are essential for ALIX functions during cytokinesis. Altogether, this work highlights the significance of arginine methylation as a regulatory post-translational modification important for the final step of cell division, by modulating interactions between proline-rich domains and their SH3-containing partners.

cell biology↗

bioRxiv2021

OTX2 homeoprotein functions in adult choroid plexus

Choroid plexus secretes cerebrospinal fluid important for brain development and homeostasis. The OTX2 homeoprotein is critical for choroid plexus development and remains highly expressed in adult choroid plexus. Through RNA sequencing analyses of constitutive and conditional knockdown adult mouse models, we reveal putative roles for OTX2 in choroid plexus function, including cell signaling and adhesion, and show that it regulates the expression of factors secreted into cerebrospinal fluid, notably transthyretin. We show that Otx2 expression impacts choroid plexus immune and stress responses, and also affects splicing which leads to changes in mRNA isoforms of proteins implicated in oxidative stress response and DNA repair. Through mass spectrometry analysis of OTX2 protein partners in the choroid plexus, and in known non-cell autonomous target regions such as visual cortex and ventricular-subventricular zone, we identified putative targets involved in cell adhesion, chromatin structure and RNA processing. Thus, OTX2 retains important roles in choroid plexus function and brain homeostasis throughout life.

neuroscience↗

bioRxiv2018

DET1-mediated degradation of a SAGA-like deubiquitination module controls H2Bub homeostasis

DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bub) over most genes by controlling the stability of a plant deubiquitination module (DUBm). In contrast with yeast and metazoan DUB modules that are associated with the large SAGA complex, the Arabidopsis DUBm only comprises three proteins (hereafter named SGF11, ENY2 and UBP22) and appears to act independently as a major H2Bub deubiquitinase activity. Our study further unveils that DET1-DDB1-Associated-1 (DDA1) protein interacts with SGF11 in vivo, linking the DET1 complex to light-dependent ubiquitin-mediated proteolytic degradation of the DUBm. Collectively, these findings uncover a signaling path controlling DUBm availability, potentially adjusting H2Bub turnover capacity to the cell transcriptional status.

plant biology↗