At the metaphase to anaphase transition, APC/C bound to Cdc20 targets cyclins A /B and securin for degradation.

TLS Online TPP Program

#Id: 9467

#Unit 4. Cell Communication and Cell Signaling

SH2 domain of STAT binds to a specific phosphotyrosine in the cytosolic domain of an activated receptor

TLS Online TPP Program

#Id: 9468

#Unit 4. Cell Communication and Cell Signaling

Erythropoietin receptor & the receptors for GH, prolactin, G-CSF, activates STAT5 but not STATs 1, 2, 3, or 4. 

TLS Online TPP Program

#Id: 9469

#Unit 4. Cell Communication and Cell Signaling

IL-2 receptor complex activates

STATs 1, 3, and 5 but not STATs 2 or 4

TLS Online TPP Program

#Id: 9470

#Unit 4. Cell Communication and Cell Signaling

Phosphorylated STAT dissociates spontaneously from the receptor, and two phosphorylated STAT proteins form a homodimer.

TLS Online TPP Program

#Id: 9471

#Unit 4. Cell Communication and Cell Signaling

STAT5 becomes activated in erythroid progenitor cells and induces expression of the protein Bcl-xL.

TLS Online TPP Program

#Id: 9472

#Unit 4. Cell Communication and Cell Signaling

Two mechanisms for terminating cytokine signaling:

1. Short-term regulation: SHP1

2. Long-term regulation: SOCS proteins