It has become increasingly difficult to find an area of cell biology in which lipids do not have important, if not key, roles as signalling and regulatory molecules. The rapidly expanding field of bioactive lipids is exemplified by many sphingolipids, such as ceramide, sphingosine, sphingosine-1-phosphate (S1P), ceramide-1-phosphate and lyso-sphingomyelin, which have roles in the regulation of cell growth, death, senescence, adhesion, migration, inflammation, angiogenesis and intracellular trafficking. Deciphering the mechanisms of these varied cell functions necessitates an understanding of the complex pathways of sphingolipid metabolism and the mechanisms that regulate lipid generation and lipid action.

Principles of bioactive lipid signalling: lessons from sphingolipids

Signaling--2000 and beyond.

Fluorescent probes are one of the cornerstones of real-time imaging of live cells and a powerful tool for cell biologists. They provide high sensitivity and great versatility while minimally perturbing the cell under investigation. Genetically-encoded reporter constructs that are derived from fluorescent proteins are leading a revolution in the real-time visualization and tracking of various cellular events. Recent advances include the continued development of 'passive' markers for the measurement of biomolecule expression and localization in live cells, and 'active' indicators for monitoring more complex cellular processes such as small-molecule-messenger dynamics, enzyme activation and protein-protein interactions.

/pdf/creating-new-fluorescent-probes-for-cell-biology-4l24l7b55e.pdf

Creating new fluorescent probes for cell biology.

Protein Kinase C: Structure, Function, and Regulation

Members of the mammalian protein kinase C (PKC) superfamily play key regulatory roles in a multitude of cellular processes, ranging from control of fundamental cell autonomous activities, such as proliferation, to more organismal functions, such as memory. However, understanding of mammalian PKC signalling systems is complicated by the large number of family members. Significant progress has been made through studies based on comparative analysis, which have defined a number of regulatory elements in PKCs which confer specific location and activation signals to each isotype. Further studies on simple organisms have shown that PKC signalling paradigms are conserved through evolution from yeast to humans, underscoring the importance of this family in cellular signalling and giving novel insights into PKC function in complex mammalian systems.

/pdf/the-extended-protein-kinase-c-superfamily-123ce50z7t.pdf

The extended protein kinase C superfamily.

Phosphorylation of the immunomodulatory drug FTY720 by sphingosine kinases.

Spatially resolved fluorescence resonance energy transfer (FRET) measured by fluorescence lifetime imaging microscopy (FLIM), provides a method for tracing the catalytic activity of fluorescently tagged proteins inside live cell cultures and enables determination of the functional state of proteins in fixed cells and tissues. Here, a dynamic marker of protein kinase Cα (PKCα) activation is identified and exploited. Activation of PKCα is detected through the binding of fluorescently tagged phosphorylation site–specific antibodies; the consequent FRET is measured through the donor fluorophore on PKCα by FLIM. This approach enabled the imaging of PKCα activation in live and fixed cultured cells and was also applied to pathological samples.

https://science.sciencemag.org/content/sci/283/5410/2085.full.pdf

Imaging Protein Kinase Cα Activation in Cells

Sphingosine kinase type 2 is essential for lymphopenia induced by the immunomodulatory drug FTY720

Phosphorylation of protein kinase C-alpha on serine 657 controls the accumulation of active enzyme and contributes to its phosphatase-resistant state.

https://www.cell.com/current-biology/pdf/S0960-9822(02)70678-7.pdf

Frédéric Bornancin

Papers

Phosphorylation of the immunomodulatory drug FTY720 by sphingosine kinases.

Imaging Protein Kinase Cα Activation in Cells

Sphingosine kinase type 2 is essential for lymphopenia induced by the immunomodulatory drug FTY720

Phosphorylation of protein kinase C-alpha on serine 657 controls the accumulation of active enzyme and contributes to its phosphatase-resistant state.

Phosphorylation of threonine 638 critically controls the dephosphorylation and inactivation of protein kinase Cα