Integrated Calendar

Proteins are large organic molecules that play a vital role in all biological organisms. Fractals are geometrical objects that possess self-similarity. Recent studies have shown that proteins resemble fractals. This observation allowed us to harness the vast mathematical and physical machinery, originally developed during the study of ideal fractal systems, in order to quantitatively analyze protein structure and dynamics. Quite unexpectedly, while studying proteins, we have also deepened our understanding of the relations between thermal vibrations of elastic networks and random walk on these networks. In particular we have shown that the solution for the mean first passage time problem on fractals is readily obtained using ananalysis of thermal vibrations.
I will survey the work we have done in thepast few years. Prior knowledge on proteins/fractals/random walk will not be assumed.

The Krupple-associated box-containing zinc-finger proteins (KRAB-ZNFss) make up one of the largest family of transcription factors. Several members of the KRAB–ZFPs modulate cell growth, survival and are implicated in malignant disorders. However, most members are not well characterized and their functions are largely unknown. Here we report that ZNF251, a member of KRAB–ZNFs, interacts with Mdm2 and promote apoptosis. Ectopic expression of ZNF251 led to enhancement of apoptosis, and enhanced expression of proapoptotic genes such as Bax and CD95. Downregulation of ZNF251 by siRNA "rescued" cells from 5FU induced cell death. Furthermore, the apoptotic effect of ZNF251 was p53-dependent and achieved through regulation of PML nuclear bodies. Thus, we have identified a novel function of KRAB-ZNF251 associated with p53-dependent apoptosis.