internship ppt on smartinternz platform as salesforce developer
Apoptosis for first semester
1. Apoptosis
Apoptosis is only one form of programmed cell death.
In animal cells, cell necrosis is another form of programmed cell
death.
2. Two distinct forms of cell death – apoptosis and necrosis
Programmed cell death eliminates unwanted cells
3. In metazoans, apoptosis is vital for
- normal development
- maintenance of tissue homeostasis
- an effective immune system
Its disturbance is implicated in numerous pathological conditions ranging from
degenerative disorders to autoimmunity to cancer
Sculpting the digits in the developing mouse paw by apoptosis
5. Apoptotic cells are biochemically recognizable
Characteristic biochemical changes in cells undergoing apoptosis
1. Chromosomal DNA cleaved into fragments
2. Change in the plasma membrane – phosphatidylserine
in the outer leaflet
3. Loss of electrical potential across the inner membrane of the
mitochondria
4. Relocation of cytochrome c from the intermembrane space of
the mitochondria to the cytosol
7. Apoptosis depends on an intracellular proteolytic cascade that is
mediated by caspases
Procaspase activation during apoptosis
8. Some human caspases
Caspases involved in inflammation caspases 1 (ICE), 4, 5
Caspases involved in apoptosis
Initiator caspases caspases 2, 8, 9, 10
Executioner caspases caspases 3, 6, 7
Examples of target proteins
Nuclear lamins
Protein that holds the endonuclease in an inactive state
Components of the cytoskeleton and cell-cell adhesion proteins
9.
10. The two best understood signaling pathways that activate a
caspase cascade in mammalian cells are the
extrinsic pathway and the intrinsic pathway
Each pathway uses its own initiator procaspases
and activation complex
11. Cell-surface death receptors activate the extrinsic pathway
of apoptosis
The extrinsic pathway of apoptosis activated through Fas death receptors
14. Bcl2 proteins regulate the intrinsic pathway of apoptosis
The three classes of Bcl2 proteins
15. The three major mammalian factions of the Bcl-2 family. The BH3-only proteins
(yellow) are essential initiators of apoptosis that primarily antagonize their pro-
survival relatives (blue), whereas either Bax or Bak (red) is required downstream
of Bcl-2.
16. The role of BH123 pro-apoptotic Bcl2 proteins (mainly Bax and Bak) in the
release of mitochondrial intermembrane proteins in the intrinsic pathway of
apoptosis