GRK–β-arrestin pathway, suppress signaling by GPCRs, actually functions as a switch, turning off signaling by G proteins and turning on other signaling pathways.

TLS Online TPP Program

#Id: 9373

#XL - T Zoology

Smad7 binds to the activated RI receptors and blocks its ability to phosphorylate Smad2 or Smad3. 

TLS Online TPP Program

#Id: 9374

#XL - T Zoology

Like SOCS proteins in the cytokine signaling, 

Smad7 also recruits an E3 ubiquitin ligase that targets TGF-β receptors for degradation.

TLS Online TPP Program

#Id: 9446

#XL - T Zoology

The cytokines form a family of relatively small, secreted signaling molecules:

Contain about 160–200 AA

4 long, conserved α helices

Control growth and differentiation

TLS Online TPP Program

#Id: 9447

#XL - T Zoology

Large family of cytokines:

Interleukins

Interferons

Growth hormone

Prolactin

G-CSF

Thrombopoietin

Erythropoietin

TLS Online TPP Program

#Id: 9448

#XL - T Zoology

Receptor Homodimerization 

Cytokines (erythropoietin) activate receptors by forming dimers of two identical cytokine receptor proteins

TLS Online TPP Program

#Id: 9450

#XL - T Zoology

Receptor hetero-dimerization or hetero-oligomerization 

Other cytokines (interleukins and interferons) bind simultaneously to two or more different cytokine receptors