Rho proteins and the p38-MAPK pathway are important mediators for LPS-induced interleukin-8 expression in human endothelial cells.

Bacterial endotoxin (lipopolysaccharide, or LPS) has potent proinflammatory properties by acting on many cell types, including endothelial cells. Secretion of the CXC-chemokine interleukin-8 (IL-8) by LPS-activated endothelial cells contributes substantially to the inflammatory response. Using human umbilical vein endothelial cells (HUVECs), we analyzed the role of small GTP-binding Rho proteins and p38 mitogen-activated protein kinase (MAPK) for LPS-dependent IL-8 expression in endothelial cells.

Forms AI and AII DNA-dependent RNA polymerases as components of two defined pools of polymerase activity in mammalian cells.

Two species of form A (or I) RNA polymerase have been identified in eucaryotic cells and there is evidence that this alpha-amanitin-insensitive activity exists as two discrete pools: a pool of 'free' activity, which is identified by its ability to transcribe poly d(A-T) in the presence of actinomycin in vitro, and a pool of enzyme in the form of a transcription complex ('engaged') which is unaffected by inhibitors of initiation of RNA synthesis. 1. The principles underlying and the practical application of the technique used to define the pool of 'free' RNA polymerase activity have been analysed in considerable detail.