Studying Organelle Dynamics in B Cells During Immune Synapse Formation.

Recognition of surface-tethered antigens by the B cell receptor (BCR) triggers the formation of an immune synapse (IS), where both signaling and antigen uptake are coordinated. IS formation involves dynamic actin remodeling accompanied by the polarized recruitment to the synaptic membrane of the centrosome and associated intracellular organelles such as lysosomes and the Golgi apparatus. Initial stages of actin remodeling allow B cells to increase their cell surface and maximize the quantity of antigen-BCR complexes gathered at the synapse.

KDEL receptor regulates secretion by lysosome relocation- and autophagy-dependent modulation of lipid-droplet turnover.

Inter-organelle signalling has essential roles in cell physiology encompassing cell metabolism, aging and temporal adaptation to external and internal perturbations. How such signalling coordinates different organelle functions within adaptive responses remains unknown. Membrane traffic is a fundamental process in which membrane fluxes need to be sensed for the adjustment of cellular requirements and homeostasis.

Motility modulation by the small non-coding RNA SroC in Salmonella Typhimurium.

Bacterial regulatory networks of gene expression include the interaction of diverse types of molecules such as the small non-coding RNAs (sRNAs) and their cognate messenger RNAs (mRNAs). In this study, we demonstrated that the Salmonella Typhimurium sRNA SroC is significantly expressed between the late-exponential and stationary phase of growth in an rpoS-dependent manner. The expression of flagellar genes predicted as targets of this sRNA was quantitatively analyzed in both a ΔsroC mutant and a SroC-overexpressing (pSroC) strain.

The small RNA RyhB homologs from Salmonella typhimurium participate in the response to S-nitrosoglutathione-induced stress.

Typically, the expression of sRNAs is activated in response to environmental stimuli in order to regulate gene expression through post-transcriptional mechanisms. In the present work we show that the Salmonellatyphimurium paralogous sRNAs RyhB-1 and RyhB-2 are induced in response to the nitrosating agent S-nitrosoglutathione (GSNO). Inactivation of these sRNAs decreased S.