Most capillary walls are relatively impermeable to the proteins in plasma, and the proteins exert an osmotic force of about 25 mm Hg across the capillary wall (oncotic pressure) that pulls water into the blood.

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

TLS Online TPP Program

#Id: 9473

#Unit 4. Cell Communication and Cell Signaling

SHP1 a phosphotyrosine phosphatase, contains:

SH2 domain  & Phosphatase domain