RNAi screen for telomerase reverse transcriptase transcriptional regulators identifies HIF1alpha as critical for telomerase function in murine embryonic stem cells.

In various types of stem cells, including embryonic stem (ES) cells and hematopoietic stem cells, telomerase functions to ensure long-term self-renewal capacity via maintenance of telomere reserve. Expression of the catalytic component of telomerase, telomerase reverse transcriptase (Tert), which is essential for telomerase activity, is limiting in many types of cells and therefore plays an important role in establishing telomerase activity levels. However, the mechanisms regulating expression of Tert in cells, including stem cells, are presently poorly understood.

Selectively guanidinylated derivatives of neamine. Syntheses and inhibition of anthrax lethal factor protease.

A series of mono-, di-, and tri-guanidinylated derivatives of neamine were prepared via selective guanidinylation of neamine. These molecules represent a novel scaffold as inhibitors of anthrax lethal factor zinc metalloprotease. Methods for the synthesis of these compounds are described, and structure-activity relationships among the series are analyzed.