1. An In Silico Assay for Apoptosis in Yeast Lou Lieto John Eberth

2. Introduction n The existence of apoptotic proteins in yeast would provide information on the origin of apoptosis in multicellular organisms n Homology between Human and C.elegans apoptotic proteins and yeast proteins was examined n Implications for yeast

3. Apoptosis in yeast n Apoptosis in single celled organisms is counter-intuitive n One would expect that apoptosis in single celled organisms would rather quickly select it’s genome for extinction n However in single celled organisms that form colonies it is the survival of the colony rather than that of individual members that ensures the survival of the genome

4. Apoptotic vs. Oncotic Death n Apoptosis n Karyorhexis –Budding- membrane shrinkage n Chromatin clumping –Regular cleavage of the DNA by a endonuclease n Lack of Inflamation n Oncosis n Karyolysis –Blebbing-increased membrane permeability n Random DNA breakage n Inflamation –Release of cellular contents

6. Human and C.elegans Proteins n HUMAN n Caspases 1-9 n Bcl-2 n Bax n Bik n Bad n P53 n Cytochrome C n Tradd n Fadd n Flice n C.elegans n Ced 1-10

7. Techniques n Human and C. elegans proteins were blasted against the S. Cerevisiae database in Genbank n The Hits were then entered into the Global Gene Hunter which checks 8 databases for the ORF in question n The results were studied for homology and any similar activity to the original search protein

8. Results n Homology with yeast n Caspases 1-945% Av. n Ced 1-1052% Av. n Bcl-2 64% n Bax 42% n Bik42% n Bad 56% n P53 32% n Cytochrome C76% n Tradd47% n Fadd46% n Flice 44%

9. Cytochrome C n Human Cytochrome C shared a 76% homology with Yeast Cytochrome C n This is to be expected considering that Cytochrome C plays an essential role in electron transport in the mitochondrial respiratory chain

10. Global Gene Hunter n Except for Cytochrome C the gene hunter either failed to return any information regarding the ORFs in question or else it identified the yeast proteins as having a function dissimilar to that of the search protein

11. What This Means n Human Caspase 1 and Ced 3 have closely related functions yet only share a 29 % identity n It is possible that some of the ORFs that are unidentified yet share a low homology with their search proteins have similar activity

12. Future Areas of Study n Apoptosis in yeast needs to be identified via morphological or histological methods, such as the TUNEL assay n The Yeast genome needs better organization and full identification of protein functions