Apoptosis Flashcards
What is Necrosis
It is where it releases cellular proteins that the immune system doesn’t know
What can necrosis do
Chronic inflamantation
What are the steps of apoptosis
Chromatin compaction and segregation and codenstation of cytoplasma the intracellular contents protect these parts now go into phagocytosis
What are the advantages of Caenorhabditis elegans
Small
Transparent
Every single cell has been maped out
Genome fully sequenced
Many gentic mutants
How many cells are there in C. elegans and many die
1090 newborn cells and 131 cells die during development leaving 959 cells left
What is an undead cells
It is where cells that were suppose to die didn’t die
What does ced-4 ced-3 non mutated do
Normally functions it produces cell death
What does a mutated ced-4 ced-3 do
It creates undead cells prevents the cells from dying
What does a normal ced-9 gene do
Prevent apotopsis a surival gene
What does a mutated ced-9 do
All cells die by apoptosis during embryogenesis
What is a caspase
Cysteine-dependent aspartate directed proteases
What is CED3 in humans
Caspase 9
What are the two types of caspases
Initiator caspases - activates effector caspases by cleaving them
Effector- cleave other protien substrates within the cell to trigger the apoptotic process
What is the apoptosome also know as
1.4 megadalton wheel of death
What is apoptosome composed of
Apaf 2
Cytochrome c
Dimer of Caspase 9
What happens if there is no cytochrome c
Apaf-1 exists as a monomer
How many Apaf monomers make up the wheel
7
What is the equiviulaent to APAF1
CED-4
What does the wheel do once it forms
Once caspase 9 is recurited it forms a dimer and activates initiator caspase
What genes to be present to be pro survival
All BH 1-4
What are pro apoptic members
When they don’t have all four it is for Bax and form channels in the membrane
What does BH3 only protiens do
Regulate activity of Bcl-2 and Bax and Bak protiens
What does CED9 resemble
Bcl-2
What does Bcl-2 do
Inhibits apoptosis
What do BH3 proteins do in nematodes and vertebrates
In neamatodes it blocks CED-9 and in veterbrates it blocks Bcl-2
What does blocking Bcl-2 do
Bak can then go and pump cytc which will attach to apaf-1 and capase 9 to go and cleave effectors
What does blocking CED-9 do
Activates Ced-4 and ced 3 and cleave cell protiens to induce apoptosis
What can also trigger apoptosis
Loss of signal
What does binding to a signal do
Bad and 14-3-3 bind and inacatviates Bad when it is lost Bad can bind to Bcl-2 and bak can pump cyt c
What is the extrinsic apoptosis pathway
It is trigged by positive acting death signals from other cells and ligands bind to the death receptor activates initiator caspase 8 dimerizes it
What is BID
it gets cleaved from caspase-8 which then binds to Bcl-2 that then releases cyt c and activates caspase-9 which actiated effector caspases
What are two pathways of apoptotic pathways
Death signal
Trophic Factor withdrawl
How does alzhemiers work
When there is an increased apoptosis a loss of neurons by aptosis
What happens when there is too little apoptosis
- Developmental defects
- Cancer
-Weekened immunity
What is too much apoptosis
- Neurodegenerative disorders (Alzheimer’s disease, Parkinson disease)
- Ischemia/ reperfusion associated injury
Autoimmune disease
What is ischemia
Stroke depeltion of o2 blood to tissue low to high O2 if the clot resolves
