Biology subjects

Guillou, F.

Publications and source records attributed to Guillou, F..

4 recordsLinked to original sources

bioRxiv2025

The piggyBac derived transposase 5 (PGBD5) can interact with human piggyBac-like elements

PGBD5 is encoded by a gene domesticated at the chordate origin from a DNA transposon of the piggyBac family. During its evolution, PGBD5s sequence has been under strong purifying selection among vertebrate genomes. This suggests PGBD5 functions in the development and physiology of chordates, as recently demonstrated in mouse and human brain development, where it was implicated in double strand DNA breaks on neurons. However, biochemical PGBD5 activities remain undefined due to lack of appropriate in vitro model systems. Furthermore, coevolution of PGBD5 with hosts has likely reshaped some of its functions, resulting in differences between vertebrate PGBD5 and the insect piggybac transposase (PB). Recent studies have found that PGBD5 can interact with two different "species" of piggyBac-like transposon element (pble). Here, we show that human PGBD5 can interact with four "species" human pbles and to promote their chromosomal integration in cells, a property it shares with insect PB. Human PGBD5 can also bind to distinct chromosomal copies of human pble in cell type-specific manner, and to genomic loci containing inverted repeats in human cells akin to those found in subterminal insect pble ends. These findings expand the scope of potential biological activities of PGBD5 and other domesticated DNA transposases.

genomics↗

bioRxiv2025

LHR and Gαs trafficking drive sustained cAMP signalling from endosomes to control steroidogenesis

1.A growing number of G protein-coupled receptors (GPCRs) signal through G proteins from intracellular compartments following endocytosis. While for few receptors the physiological relevance of such mechanism has been established, the relationships between the spatio-temporal organization of cellular signalling and the physiological responses are still to be elucidated for most receptors. Signalling by the luteinizing hormone receptor (LHR) is essential to regulate sex steroids production in gonads, but how G protein-dependent signals from endosomes are functionally important for steroidogenesis remains unexplored. Here, we demonstrate that transient LHR activation promotes a prolonged Gs/cAMP signalling from endosomes, which requires ligand-induced independent receptor and Gs trafficking. We show that endosomal trafficking is specifically required for ligand-induced cAMP accumulation in the nucleus and gene expression, as well as for steroids production in Leydig cells. Thus, this study contributes to further understand the molecular mechanisms by which LHR, through signalling compartmentalization, controls gonadal steroidogenesis.

cell biology↗

bioRxiv2024

Hormone-regulated dynamics of mRNA distribution on ribosomes in Sertoli cells

The effects of hormone stimulation on the cell translational profile remain poorly understood. Here, using polysome profiling combined to RNA sequencing, we analyzed the translational response to follicle-stimulating hormone (FSH) of primary rat Sertoli cells, that exhibit an active anabolic activity regulated by reproductive hormones in the male gonad. We first established that mRNA distribution to polysomes follows a bimodal pattern, with 15% of mRNAs enriched in polysomes and exhibiting high expression. Critically, this basal polysomal enrichment had a major impact on FSH-induced mRNA recruitment to the polysomes, since FSH stimulation promoted the release of polysome-enriched mRNAs, while mRNAs that were the least associated to polysomes were preferentially recruited to polysomes upon stimulation. The FSH signal did not alter the core biological functions of Sertoli cells, but shifted the proteins involved in these functions, suggesting a molecular rewiring of the FSH-induced gene expression. These findings underscore how ribosomal reallocation dynamically adapts the cellular translatome to microenvironmental changes, enabling cells to fine-tune protein production in response to external stimuli. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/629416v1_ufig1.gif" ALT="Figure 1000"> View larger version (19K): org.highwire.dtl.DTLVardef@27334forg.highwire.dtl.DTLVardef@199c630org.highwire.dtl.DTLVardef@a28b92org.highwire.dtl.DTLVardef@1794172_HPS_FORMAT_FIGEXP M_FIG C_FIG Bullet points* In Sertoli cells, most mRNAs distribute similarly between monosomes and polysomes, but a sub-population is specifically enriched in polysomes * Basal polysomal enrichment level has a major impact on FSH-induced mRNA recruitment or release from the polysomes * The FSH signal induced a global rewiring of the proteins involved in Sertoli cell basal activity * FSH-induced reassignment of ribosomes to specific mRNAs has to comply with a tightly maintained mRNA distribution landscape

systems biology↗

bioRxiv2020

PKA drives paracrine crisis and WNT4-dependent testis tumor in Carney complex

Large Cell Calcifying Sertoli Cell Tumors (LCCSCTs) are among the most frequent lesions occurring in Carney complex (CNC) male patients. Although they constitute a key diagnostic criterion for this rare multiple neoplasia syndrome resulting from inactivating mutations of the tumor suppressor PRKAR1A leading to unrepressed PKA activity, the LCCSCT pathogenesis and origin remain elusive. Mouse models targeting Prkar1a inactivation in all somatic populations or separately in each cell type were generated to decipher the molecular and paracrine networks involved in the CNC testis lesion induction. We demonstrate that Prkar1a mutation is required in both stromal and Sertoli cells for the occurrence of LCCSCT. Integrative analyses comparing transcriptomic, immunohistological data and phenotype of mutant mouse combinations led to understand the human LCCSCT pathogenesis and demonstrated unprecedented PKA-induced paracrine molecular circuits in which the aberrant WNT4 signal production is a limiting step in shaping intratubular lesions and tumor expansion both in mouse model and human CNC testes.

pathology↗