A New in Silico Antibody Similarity Measure Both Identifies Large Sets of Epitope Binders with Distinct CDRs and Accurately Predicts Off-Target Reactivity

Developing a therapeutic antibody is a long, tedious, and expensive process. Many obstacles need to be overcome, such as biophysical properties (issues of solubility, stability, weak production yields, etc.), as well as cross-reactivity and subsequent toxicity, which are major issues. No in silico method exists today to solve such issues. We hypothesized that if we were able to properly measure the similarity between the CDRs of antibodies (Ab) by considering not only their evolutionary proximity (sequence identity) but also their structural features, we would be able to identify families of Ab recognizing similar epitopes. As a consequence, Ab within the family would share the property to recognize their targets, which would allow (i) to identify off-targets and forecast the cross-reactions, and (ii) to identify new Ab specific for a given target. Testing our method on 238D2, an antagonistic anti-CXCR4 nanobody, we were able to find new nanobodies against CXCR4 and to identify influenza hemagglutinin as an off-target of 238D2

Régulation de la traduction des ARN messagers par l'hormone folliculo-stimulante

Diplôme : Dr. d'Universit

Regulation of messengers RNA's translation by the Follicicle-stimulating hormone

La FSH est une hormone clé de la régulation de la fonction de reproduction. La compréhension de ses mécanismes moléculaires est essentielle pour en apprécier pleinement les effets biologiques. Nous montrons ici que la FSH ne régule pas seulement la transcription de ses gènes cibles comme il l’était pensé jusqu’alors mais également leur traduction. Elle active ainsi à la fois la traduction cap-dépendante et IRES-dépendante dans les cellules de Sertoli du testicule. La p70S6K participe à ces mécanismes. En réponse à la FSH, elle est activée et recrutée à la coiffe m7GTP des ARNm où elle phosphoryle ses cibles traductionnelles. La p70S6K est par ailleurs différentiellement régulée au cours du développement sertolien par les voies PI3K et PKA. Cette activation différentielle a été reproduite à l’aide d’un modèle mathématique dynamique qui a permis de générer des données inaccessibles par l’expérimentation. Les β-arrestines, qui sont des transducteurs spécifiques des GPCR semblent participer à l’activation de la p70S6K par la FSH. Ce travail ouvre des perspectives quant à l’identification de mécanismes de régulation de la traduction dépendants des GPCR.FSH is one of the hormones that control the reproductive function. A clear understanding of its molecular mechanisms is essential to fully appreciate its biological effects. Here we show that FSH regulates the expression of its target genes not only at the transcriptional level as it was thought until recently, but also at the translational level. FSH activates cap-dependent as well as IRES-dependent translation in Sertoli cells of the testis. p70S6K participates in this mechanisms. In response to FSH, p70S6K is activated, is recruited to the m7GTP cap structure of the mRNA where it phosphorylates it translational targets. Furthermore, p70S6K is differentially activated during Sertoli cell development by the PI3K and PKA pathways. This differential activation has been described in a mathematic dynamic model that provided experimentally inaccessible data. β-arrestins, which are specific transducers of GPCR, seem to participate in FSH-induced p70S6K activation. This work opens exciting avenues in the identification of new translational control mechanisms dependent on GPCR

Régulation de la Traduction des ARN messagers par l'Hormone Folliculo-Stimulante

La FSH est une hormone clé de la régulation de la fonction de reproduction. La compréhension de ses mécanismes moléculaires est essentielle pour en apprécier pleinement les effets biologiques. Nous montrons ici que la FSH ne régule pas seulement la transcription de ses gènes cibles comme il l était pensé jusqu alors mais également leur traduction. Elle active ainsi à la fois la traduction cap-dépendante et IRES-dépendante dans les cellules de Sertoli du testicule. La p70S6K participe à ces mécanismes. En réponse à la FSH, elle est activée et recrutée à la coiffe m7GTP des ARNm où elle phosphoryle ses cibles traductionnelles. La p70S6K est par ailleurs différentiellement régulée au cours du développement sertolien par les voies PI3K et PKA. Cette activation différentielle a été reproduite à l aide d un modèle mathématique dynamique qui a permis de générer des données inaccessibles par l expérimentation. Les b-arrestines, qui sont des transducteurs spécifiques des GPCR semblent participer à l activation de la p70S6K par la FSH. Ce travail ouvre des perspectives quant à l identification de mécanismes de régulation de la traduction dépendants des GPCR.FSH is one of the hormones that control the reproductive function. A clear understanding of its molecular mechanisms is essential to fully appreciate its biological effects. Here we show that FSH regulates the expression of its target genes not only at the transcriptional level as it was thought until recently, but also at the translational level. FSH activates cap-dependent as well as IRES-dependent translation in Sertoli cells of the testis. p70S6K participates in this mechanisms. In response to FSH, p70S6K is activated, is recruited to the m7GTP cap structure of the mRNA where it phosphorylates it translational targets. Furthermore, p70S6K is differentially activated during Sertoli cell development by the PI3K and PKA pathways. This differential activation has been described in a mathematic dynamic model that provided experimentally inaccessible data. b-arrestins, which are specific transducers of GPCR, seem to participate in FSH-induced p70S6K activation. This work opens exciting avenues in the identification of new translational control mechanisms dependent on GPCR.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

GPCR signalling to the translation machinery

International audienceG protein-coupled receptors (GPCRs) are involved in most physiological processes, many of them being engaged in fully differentiated cells. These receptors couple to transducers of their own, primarily G proteins and beta-arrestins, which launch intracellular signalling cascades. Some of these signalling events regulate the translational machinery to fine-tune general cell metabolism or to alter protein expression pattern. Though extensively documented for tyrosine kinase receptors, translational regulation by GPCRs is still poorly appreciated. The objective of this review paper is to address the following questions: i) is there a "GPCR signature" impacting on the translational machinery, and ultimately on the type of mRNA translated? ii) are the regulatory networks involved similar as those utilized by tyrosine kinase receptors? In particular, we will discuss the specific features of translational control mediated by GPCRs and highlight the intrinsic properties of GPCRs these mechanisms could rely on. (C) 2009 Elsevier Inc. All rights reserved

G Protein-Coupled Receptors As Regulators of Localized Translation: The Forgotten Pathway?

G protein-coupled receptors (GPCRs) exert their physiological function by transducing a complex signaling network that coordinates gene expression and dictates the phenotype of highly differentiated cells. Much is known about the gene networks they transcriptionally regulate upon ligand exposure in a process that takes hours before a new protein is synthesized. However, far less is known about GPCR impact on the translational machinery and subsequent mRNA translation, although this gene regulation level alters the cell phenotype in a strikingly different timescale. In fact, mRNA translation is an early response kinetically connected to signaling events, hence it leads to the synthesis of a new protein within minutes following receptor activation. By these means, mRNA translation is responsive to subtle variations of the extracellular environment. In addition, when restricted to cell subcellular compartments, local mRNA translation contributes to cell micro-specialization, as observed in synaptic plasticity or in cell migration. The mechanisms that control where in the cell an mRNA is translated are starting to be deciphered. But how an extracellular signal triggers such local translation still deserves extensive investigations. With the advent of high-throughput data acquisition, it now becomes possible to review the current knowledge on the translatome that some GPCRs regulate, and how this information can be used to explore GPCR-controlled local translation of mRNAs

G Protein-Coupled Receptors As Regulators of Localized Translation: The Forgotten Pathway?

International audienceG protein-coupled receptors (GPCRs) exert their physiological function by transducing a complex signaling network that coordinates gene expression and dictates the phenotype of highly differentiated cells. Much is known about the gene networks they transcriptionally regulate upon ligand exposure in a process that takes hours before a new protein is synthesized. However, far less is known about GPCR impact on the translational machinery and subsequent mRNA translation, although this gene regulation level alters the cell phenotype in a strikingly different timescale. In fact, mRNA translation is an early response kinetically connected to signaling events, hence it leads to the synthesis of a new protein within minutes following receptor activation. By these means, mRNA translation is responsive to subtle variations of the extracellular environment. In addition, when restricted to cell subcellular compartments, local mRNA translation contributes to cell micro-specialization, as observed in synaptic plasticity or in cell migration. The mechanisms that control where in the cell an mRNA is translated are starting to be deciphered. But how an extracellular signal triggers such local translation still deserves extensive investigations. With the advent of high-throughput data acquisition, it now becomes possible to review the current knowledge on the translatome that some GPCRs regulate, and how this information can be used to explore GPCR-controlled local translation of mRNAs

Developmentally regulated integration of PKA- and PI-3 kinase-mediated signalling on p70S6K by the FSH-R

International audienc