Matrix metalloproteinases 9 and 10 inhibit protein kinase C-potentiated, p53-mediated apoptosis.

p53, a major sensor of DNA damage, is a transcription factor that, depending on its phosphorylation status, regulates the cell cycle, DNA repair, or apoptosis. The protein kinase C (PKC) family of isozymes is also implicated in cell cycle and programmed cell death (PCD) control and has recently been shown to influence p53 function. Using three human colon adenocarcinoma cell lines SW480, EB-1, and HCT116 that either lack p53 function and were engineered to express inducible wild-type p53 (wt p53), or that constitutively express wt p53, we show that phorbol ester-mediated PKC activation potentiates p53-induced PCD.

Dynamic confinement of NK2 receptors in the plasma membrane. Improved FRAP analysis and biological relevance.

A functional fluorescent neurokinin NK2 receptor, EGFP-NK2, was previously used to follow, by fluorescence resonance energy transfer measurements in living cells, the binding of its fluorescently labeled agonist, bodipy-neurokinin A (NKA). Local agonist application suggested that the activation and desensitization of the NK2 receptors were compartmentalized at the level of the plasma membrane. In this study, fluorescence recovery after photobleaching experiments are carried out at variable observation radius (vrFRAP) to probe EGFP-NK2 receptor mobility and confinement.