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An In Silico Assay for Apoptosis in Yeast. Lou Lieto John Eberth. Introduction. The existence of apoptotic proteins in yeast would provide information on the origin of apoptosis in multicellular organisms Homology between Human and C.elegans apoptotic proteins and yeast proteins was examined - PowerPoint PPT Presentation
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An In Silico Assay for An In Silico Assay for Apoptosis in YeastApoptosis in Yeast
Lou LietoLou LietoJohn EberthJohn Eberth
IntroductionIntroduction The existence of apoptotic proteins The existence of apoptotic proteins
in yeast would provide information in yeast would provide information on the origin of apoptosis in on the origin of apoptosis in multicellular organismsmulticellular organisms
Homology between Human and Homology between Human and C.elegans apoptotic proteins and C.elegans apoptotic proteins and yeast proteins was examinedyeast proteins was examined
Implications for yeastImplications for yeast
Apoptosis in yeastApoptosis in yeast
Apoptosis in single celled organisms is Apoptosis in single celled organisms is counter-intuitivecounter-intuitive
One would expect that apoptosis in single One would expect that apoptosis in single celled organisms would rather quickly select celled organisms would rather quickly select it’s genome for extinctionit’s genome for extinction
However in single celled organisms that form However in single celled organisms that form colonies it is the survival of the colony rather colonies it is the survival of the colony rather than that of individual members that ensures than that of individual members that ensures the survival of the genomethe survival of the genome
Apoptotic vs. Oncotic Apoptotic vs. Oncotic DeathDeath
ApoptosisApoptosis KaryorhexisKaryorhexis
– Budding- membrane Budding- membrane shrinkageshrinkage
Chromatin clumpingChromatin clumping– Regular cleavage of Regular cleavage of
the DNA by a the DNA by a endonucleaseendonuclease
Lack of InflamationLack of Inflamation
OncosisOncosis KaryolysisKaryolysis
– Blebbing-increased Blebbing-increased membrane permeabilitymembrane permeability
Random DNA breakageRandom DNA breakage InflamationInflamation
– Release of cellular Release of cellular contentscontents
Human and C.elegans Human and C.elegans ProteinsProteins
HUMANHUMAN Caspases 1-9Caspases 1-9 Bcl-2Bcl-2 BaxBax BikBik BadBad P53P53 Cytochrome CCytochrome C TraddTradd FaddFadd FliceFlice
C.elegansC.elegans Ced 1-10Ced 1-10
TechniquesTechniques Human and C. elegans proteins were Human and C. elegans proteins were
blasted against the S. Cerevisiae blasted against the S. Cerevisiae database in Genbankdatabase in Genbank
The Hits were then entered into the The Hits were then entered into the Global Gene Hunter which checks 8 Global Gene Hunter which checks 8 databases for the ORF in questiondatabases for the ORF in question
The results were studied for homology The results were studied for homology and any similar activity to the original and any similar activity to the original search proteinsearch protein
ResultsResults Homology with yeastHomology with yeast Caspases 1-9Caspases 1-9 45% Av.45% Av. Ced 1-10Ced 1-10 52% Av.52% Av. Bcl-2 Bcl-2 64% 64% BaxBax 42%42% BikBik 42%42% BadBad 56%56% P53P53 32% 32% Cytochrome CCytochrome C 76%76% TraddTradd 47%47% FaddFadd 46%46% FliceFlice 44% 44%
Cytochrome CCytochrome C
Human Cytochrome C shared a Human Cytochrome C shared a 76% homology with Yeast 76% homology with Yeast Cytochrome CCytochrome C
This is to be expected considering This is to be expected considering that Cytochrome C plays an that Cytochrome C plays an essential role in electron transport essential role in electron transport in the mitochondrial respiratory in the mitochondrial respiratory chainchain
Global Gene HunterGlobal Gene Hunter Except for Cytochrome C the gene Except for Cytochrome C the gene
hunter either failed to return any hunter either failed to return any information regarding the ORFs in information regarding the ORFs in question or else it identified the question or else it identified the yeast proteins as having a function yeast proteins as having a function dissimilar to that of the search dissimilar to that of the search proteinprotein
What This MeansWhat This Means Human Caspase 1 and Ced 3 have Human Caspase 1 and Ced 3 have
closely related functions yet only closely related functions yet only share a 29 % identityshare a 29 % identity
It is possible that some of the ORFs It is possible that some of the ORFs that are unidentified yet share a that are unidentified yet share a low homology with their search low homology with their search proteins have similar activityproteins have similar activity
Future Areas of Future Areas of Study Study
Apoptosis in yeast needs to be Apoptosis in yeast needs to be identified via morphological or identified via morphological or histological methods, such as the histological methods, such as the TUNEL assayTUNEL assay
The Yeast genome needs better The Yeast genome needs better organization and full identification organization and full identification of protein functions of protein functions
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