Quaternary- Extinctions of large mammals, and birds; evolution of Homo sapiens, spread out of Africa

TLS Online TPP Program

#Id: 10541

#Unit 4. Cell Communication and Cell Signaling

In the absence of trophic factors, nonphosphorylated

Bad binds to Bcl-2, releasing Bax and Bak and allowing them to form oligomeric membrane pores and holes.

TLS Online TPP Program

#Id: 10542

#Unit 4. Cell Communication and Cell Signaling

DNA damage or UV irradiation leads to induction of synthesis of the BH3-only Puma protein which binds to Bak and Bax as well as to Bcl-2, allowing Bak and

Bax to form oligomeric pores.

TLS Online TPP Program

#Id: 10543

#Unit 4. Cell Communication and Cell Signaling

Removal of a cell from its substratum disrupts integrin signaling, leading to release of the BH3-only Bim

protein from the cytoskeleton which binds to Bak and Bax to promote pore formation.

TLS Online TPP Program

#Id: 10544

#Unit 4. Cell Communication and Cell Signaling

Two BH3-only proteins, Puma and Noxa are transcriptionally induced by the p53 protein

TLS Online TPP Program

#Id: 10545

#Unit 4. Cell Communication and Cell Signaling

Binding of cytochrome c to the Apaf1 triggers formation of an apoptosome containing seven molecules each of Apaf and cytochrome c and having a sevenfold symmetry. 

TLS Online TPP Program

#Id: 10546

#Unit 4. Cell Communication and Cell Signaling

Apoptosome 

a disk-shaped 1.4-MDa heptameric wheel of death