Rotation Projects:


Our lab focuses on how the terminal sequences of mammalian chromosomes—the telomeres—are protected against the DNA damage response machinery.  We know that when this protection is lost a DNA damage response is initiated at chromosome ends leading to end-to-end chromosome fusions.  The key players in this process are proteins that bind specifically to the telomere sequence, TTAGGG, and together constitute the Shelterin complex.  However, the molecular mechanisms by which these proteins perform this essential function remain elusive.



Project 1-Discovery of novel factors preventing chromosome fusions and DNA damage activation at mammalian chromosome ends.

We have identified several novel proteins that could potentially aid the shelterin complex in protecting the chromosome ends.  This project will examine the role of these proteins and identify those that contribute to different aspects of telomere protection.  To validate these proteins and their function, we will use specific shRNA to down regulate gene expression.  DNA damage foci and end-to-end chromosome fusions will be used as a readout for telomere “deprotection”.  Several basic techniques used routinely in the lab will be performed during this project such as cell culture, viral infection, immunofluorescence, metaphase spread preparation, Fluorescence In Situ Hybridizations (FISH), telomere blots and RT-PCR.



Project 2- DNA damage response in stem cells and differentiated stem cells.

The aim of this project is to test the differential outcome of acute telomere dysfunction in adult stem cells versus differentiated cell types.  This work addresses a major focus of the lab—elucidating the mechanisms that allow telomere-associated proteins to suppress tumor development and the onset of aging.  Stem cells are protected against aging and these studies will provide a real, mechanistic insight into the different pathways involved in this process. In this project we will use temporally and cell type regulated mouse strains to deplete an essential telomere-associated protein.  Using immunohistochemistry we will then test the induction of apoptosis and/or senescence following telomere dysfunction based on the cellular context.

During these rotations students will have a first-hand experience working with mouse models.  Basic techniques used will include but not be limited to: immunohistochemistry, protein isolation from tissues, Fluorescence In Situ Hybridizations (FISH) on paraffin and frozen sections and telomere blots.


For additional information and projects in the lab, please contact Eros: edenchi@scripps.edu


Review articles:

Give me a break: how telomeres suppress the DNA damage response, DNA repair, 2009 8:1118-26. PDF