Cell Death

Apoptosis

regulated cell death

Phagocytosis

the act of cell engulfment/digestion of a dead cell by phagocyte

phagocytes; eat me

Apoptotic bodies get eaten by ________ because of their _______ signal

Phosphatidylserine

“Eat me” signal on the cell membrane

inner; healthy

Phosphatidylserine is found in the _____ membrane of ______ cells

959; how; when; what

C. elegans has _______ somatic cells that follow a stereotype cell lineage pattern

This means you can predict _____ a cell divides, ______ a cell will divide and _____ a cell will become

131

Exactly ______ C. elegans somatic cells die during development, yielding 959

Ced

genes that encoded regulators of cell death

protease

The ced-3 gene encode a _______

Capases

proteases encoded by ced-3

cysteine; aspartic

Caspases have a _______ residue in their catalytic domain that cleaves their substrate at _______ residues

inactive

Capases occur as _______ precursors that are activated only during apoptosis

APAF-1

Ced-4 encodes for human _______

Apoptosome

complex formed by APAF-1 and caspase 9

BCL-2

ced-9 gene encodes for human _______

inhibitor; activators; inhibitors

BCL-2 itself is an ________ of apoptosis but the BCL-2 family of proteins can act as ________ or _________

Bid, Bax, Bak

Pro-apoptotic BCL-2 proteins

BCL-2

Anti-apoptotic BCL-2 proteins

oligomerize

Cell death causes Bax and Bak to _______

pores; outer

Bax/Bak oligomers form _______ in the mitochondrial _______ membrane

Bax/Bak; cytochrome C

Due to the pores made from _______, there will be a release of ______ from the mitochondrial inter membrane space to the cytoplasm

APAF-1; c/APAF-1; caspase 9

Cytochrome c will bind to __________ and make a ______ complex

This will recruit _________

9; 3; caspase 3

In the c/APAF-1 complex, Caspase ____ will cleave procaspase ____ to _______

C. elegans

Cytochrome C does not regulate ________ apoptosis

DISC; extrinsic

Activation of the _____ complex will activate executioner caspases

This is a form of apoptosis using the ________ pathway

Necrosis

unprogrammed cell death

protein complex

Initiator caspases form huge ______ once apoptotic signal is received

dimerize; cleave

Initiator caspases ______ and ______ each other which results in activation

initiator

Executioner caspases are cleaved by _________ causing them to form their active formation

They then are able to cleave multiple substrates

Necroptosis

Regulated Necrosis

RiPK3

kinase that is activated by TNF receptor in necrosis

MLKL; plasma membrane

RIPK3 phosphorylates ________ that oligermerizes and inserts into the ___________ and disrupts it

many; immune

Necroptosis happens in ________ cells while pyroptosis happens in ________ cells

injured; pathogen

Necroptosis is activated by released cellular of _________ cells

Pyroptosis is activated by ________ molecular motifs

caspases

Pyroptosis uses ________, necroptosis does not

Regulation of Pyroptosis 1st Part

Exposure of bacterial pathogen

Regulation of Pyroptosis 2nd Part

a series of events activates caspase 1 and caspase 11

Regulation of Pyroptosis 3rd Part

caspases cleave gasdermin D, releasing a small n-terminal fragment

Regulation of Pyroptosis 4th Part

small fragment of gasdermin D translocates to the plasma membrane and forms pores

Regulation of Pyroptosis 5th Part

the cell swells and bursts releasing pro-inflammatory molecules

Process of Entosis 1st Part

cells must detach from the extracellular matrix

Process of Entosis 2nd Part

cells then form adherens junctions between each using cadherin molecules

Process of Entosis 3rd Part

adhesion stimulates cell contractility in both cells using Rho GTPase and ROCK

Process of Entosis 4th Part

the cell that exerts the greatest contractility wins while the cell with the weaker contractility loses and becomes engulfed

prevent

Entosis can ______ cancer by engulfing the diseased cell

promote

Entosis can ______ cancer by:

• provided entotic cell with nutrients

• can result in failed cytokinesis

• promotes cell competition