The actin-based motor protein myosin II regulates MHC class II trafficking and BCR-driven antigen presentation

Antigen (Ag) capture and presentation onto major histocompatibility complex (MHC) class II molecules by B lymphocytes is mediated by their surface Ag receptor (B cell receptor [BCR]). Therefore, the transport of vesicles that carry MHC class II and BCR–Ag complexes must be coordinated for them to converge for processing. In this study, we identify the actin-associated motor protein myosin II as being essential for this process. Myosin II is activated upon BCR engagement and associates with MHC class II–invariant chain complexes. Myosin II inhibition or depletion compromises the convergence and concentration of MHC class II and BCR–Ag complexes into lysosomes devoted to Ag processing. Accordingly, the formation of MHC class II–peptides and subsequent CD4 T cell activation are impaired in cells lacking myosin II activity. Therefore, myosin II emerges as a key motor protein in BCR-driven Ag processing and presentation

A Novel Mouse c-fos Intronic Promoter That Responds to CREB and AP-1 Is Developmentally Regulated In Vivo

BACKGROUND: The c-fos proto-oncogene is an archetype for rapid and integrative transcriptional activation. Innumerable studies have focused on the canonical promoter, located upstream from the transcriptional start site. However, several regulatory sequences have been found in the first intron. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe an extremely conserved region in c-fos first intron that contains a putative TATA box, and functional TRE and CRE sites. This fragment drives reporter gene activation in fibroblasts, which is enhanced by increasing intracellular calcium and cAMP and by cotransfection of CREB or c-Fos/c-Jun expression vectors. We produced transgenic mice expressing a lacZ reporter controlled by the intronic promoter. Lac Z expression of this promoter is restricted to the developing central nervous system (CNS) and the mesenchyme of developing mammary buds in embryos 12.5 days post-conception, and to brain tissue in adults. RT-QPCR analysis of tissue mRNA, including the anlage of the mammary gland and the CNS, confirms the existence of a novel, nested mRNA initiated in the first intron. CONCLUSIONS/SIGNIFICANCE: Our results provide evidence for a novel, developmentally regulated promoter in the first intron of the c-fos gene

Mission de M. Jean Bonnerot à Rome

Bonnerot Jean. Mission de M. Jean Bonnerot à Rome. In: École pratique des hautes études, Section des sciences historiques et philologiques. Annuaire 1909-1910. 1909. pp. 108-112

Mission de M. Jean Bonnerot à Rome

Bonnerot Jean. Mission de M. Jean Bonnerot à Rome. In: École pratique des hautes études, Section des sciences historiques et philologiques. Annuaire 1909-1910. 1909. pp. 108-112

En plein vent, poésie

Bonnerot Jean. En plein vent, poésie. In: Bulletin de la Société d'histoire de la pharmacie, 14ᵉ année, n°50, 1926. pp. 1-1

Mission de Jean Bonnerot en Italie

Bonnerot Jean. Mission de Jean Bonnerot en Italie. In: École pratique des hautes études, Section des sciences historiques et philologiques. Annuaire 1910-1911. 1910. pp. 112-117

Une publication nouvelle. Études françaises

Bonnerot Jean. Une publication nouvelle. Études françaises. In: Bulletin de l'Association Guillaume Budé, n°8, juillet 1925. pp. 52-55