process of appoptosis

1. By- Nisha Lakra
M.Sc 2nd SEMESTER
DEPARTMENT OF Applied genetics
Brindavan College

2.  Apoptosis is the process of programmed cell
death.
 The word apoptosis was introduced by Kerr,
Wyllie and Currie to describe a form of cell death
distinct from necrosis.

3. Apoptosis
• Chromatin condensation
• Cell Shrinkage
• Preservation of
Organelles
and cell membranes
• Rapid engulfment by
neighboring cells
preventing inflammation
Necrosis
• Nuclear swelling
• Cell Swelling
• Disruption of Organelles
• Rupture of cell and
release
of cellular contents
• Inflammatory response

4. Apoptosis is an energy dependent programmed
cell death for removal of unwanted individual
cells

5. Death
Ligands
Effector
Caspase 3
Death
Receptors
Initiator
Caspase 8
Cell
death
DNA
damage
& p53
Mitochondria/
Cytochrome C
Initiator
Caspase 9
“Extrinsic Pathway”
“Intrinsic Pathway”

6. • They belong to a group of enzymes known as cysteine
proteases,Zymogens- inactive forms.
• Caspase 8 and 10- initiator (extrinsic)
• Caspase 9- initiator (intrinsic)
 Single chain of pro-enzymes.
 Contains an N-terminal domain, a small subunit and
a large subunit (similar to a ribosome).
 Apoptotic stimulus Activation Substrate
Cleavage Enzyme.

7.  Inflammatory Caspases: 1, 4, and 5
 Initiator Caspases: 2, 8, 9, and 10
 Long N-terminal domain
 Interact with effector caspases
 Effector Caspases: 3, 6, and 7
 Little to no N-terminal domain
 Initiate cell death

8.  It involves transmembrane death receptors that are
members of the tumor necrosis factor (TNF) receptor
gene superfamily.
 ligands of these receptors are FasL, TNF-alpha,
Apo3L, and Apo2L. Corresponding receptors are FasR,
TNFR1, DR3, and DR4/DR5, respectively.
 The signal transduction of the extrinsic pathway
involves several caspases which are proteases with
specific cellular targets.

10.  It involves non-receptor–mediated
intracellular signals, inducing activities in
the mitochondria that initiate apoptosis.
 Pro-apoptotic proteins activate caspases
that mediate the destruction of the cell
through many pathways.
 The regulation of pro-apoptotic events in
the mitochondria occurs through activity
of members of the Bcl-2 family of proteins
and the tumor suppressor protein p53.
 Members of the Bcl-2 family of proteins
may be pro- or anti-apoptotic.
 The anti-apoptotic proteins are Bcl-2, Bcl-
x, Bcl-xL, Bcl-XS, Bcl-w, and BAG.
 Pro-apoptotic proteins include Bcl-10,
Bax, Bak, Bid, Bad, Bim, Bik, and Blk.

11. Mechanism (Intrinsic)

12. IMPORTANCE OF APOPTOSIS
o Important in normal physiology / development
– Development: Immune systems maturation,
Morphogenesis, Neural development
– Adult: Immune privilege, DNA damage and wound
repair.
o Excess apoptosis
– Neurodegenerative diseases
o Deficient apoptosis
– Cancer
– Autoimmunity

13. APOPTOSIS: important in embryogenesis
Morphogenesis (eliminates excess cells):
Selection (eliminates non-functional cells):

14. APOPTOSIS: important in embryogenesis
Immunity (eliminates dangerous cells):
Self antigen
recognizing cell
Organ size (eliminates excess cells):

15. Thank you