Lecture 04 Flashcards
This gene/protein is the precursor for cell cycle arrest, senescence, or apoptosis.
p53
Similarity between quiescence and senescence
Both means cells do not proliferate.
MAIN difference of quiescence and senescence
Quiescence - due to lack of nutrition; reversible
Senescence - due to agingor serious DNA damages; mostly irreversible
Senescence or Quiescence.
Results to hypertrophic cell
Senescence
Senescence or Quiescence.
Growth without proliferation
Senescence
Senescence leads to HYPERTROPHY.
Senescence or Quiescence.
No proliferation and growth
Quiescence
Senescence or Quiescence.
Due to shortage of growth factors
Quiescence
These are markers of senescent cells
Lipofuscin
The marker of senescent cells is usually stored in which organelle
Lysosome
What are the FOUR hallmarks of senescence
- Cell Cycle Arrest
- Macromolecular Damage
- Deregulated Metabolism
- Secretory Phenotype
T or F. Senescent cells may lead to apoptosis.
True. With senolytics
T or F. Necrotic cells can lead to senescence
False
What is efferocytosis?
Phagocytosis of apoptosized* cells by immune cells
- not a real word
Necrosis or Apoptosis.
Cell lysis occurs.
N
Necrosis or Apoptosis.
One cell affected
A
Recall why.
Necrosis or Apoptosis.
Cell shrinks
A
Necrosis or Apoptosis.
Many cells are affected
N
Recall why.
Necrosis or Apoptosis.
Formation of blebbing
A
Necrosis or Apoptosis.
Cell contents are ingested by neighboring cells
A
In necrosis, cell contents are ingested by macrophage (but this is not a
T or F. The assembled adaptor-protein complex activates the initiator caspase monomers by assembling the monomers into dimers.
True
T or F. The assembled adaptor-protein complex assembles the initiator caspase monomers into a dimer and further cleaves the monomers to form the mature active initiator caspase.
False.
Which cleaves the monomers to become mature?
The monomer partners themselves (CROSS-CLEAVAGING)
T or F. The removal of the webs between the digits of mammals is caused by apoptosis.
T
T or F. The removal of the tail of frogs is caused by necrosis.
F. The removal of the tail of frogs is also caused by apoptosis.
T or F. Apoptotic cells can then undergo necrosis.
False
In both caspase proteins (initiator and executor), this subunit is cleaved to activate them.
Prodomain
Which protein activates the executioner caspase dimer. Be specific.
Mature active initiator caspase
The following are true for both initiator and executor caspase, EXCEPT:
a. They have prodomain, which is cleaved to activate the caspase proteins.
b. Both are activated by caspase protein
c. Is pro-apoptosis
d. Aids for cleavage of other proteins
B. Initiator caspase is activated by assembled adaptor-protein complex, NOT a caspase
Other name for executioner caspase
Caspase-3, 8, 9
Executor caspase activates _______ by cleaving _______
CAD; iCAD
T or F. The executor caspase acts as an inhibitor protein of CAD.
False. iCAD acts as an inhibitor protein of CAD. Executor caspase ACTIVATES CAD.
Function of active CAD
Cleaves DNA between nucleosome
T or F. Both initiator and executor caspase normally exist as an inactive monomer.
False. Only initiator caspase normally exists as an inactive monomer. Executioner caspase normally exists as an inactive DIMER.
Differentiate extrinsic and intrinsic apoptotic pathway.
Extrinsic - signal coming from outside the cell.
Intrinsic - signaled from mitochondria
Intrinsic pathway is also called the ___________.
Mitochondrial pathway
Explain extrinsic apoptotic pathway briefly
Lymphocyte’s Fas ligand activates Fas death receptor. Creates/oligomerizes DISC. DISC enables formation of executioner caspase. Executioner caspase targets apoptotic cells.
Explain intrinsic apoptotic pathway briefly.
Release of cytochrome c to cytosol. Cyt c binds to inactive Apaf 1 to become active Apaf1. Apaf1 oligomerizes into an apoptosome. Executioner caspase is made.
Pro-apoptotic Bcl2 family effectors
Bak, Bax
Anti-apoptotic Bcl2 family proteins
Bcl2, BclxL, Mcl1
Pro-apoptotic (anti-anti-apoptotic) BH3-only proteins
Bad, Bim, Bid, Puma, Noxa
