In the dark, most transducin is localized to the outer segment, while most arrestin is found in other parts of the cell; in this condition, vision is most sensitive to very low light levels.

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#Id: 9374

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Like SOCS proteins in the cytokine signaling, 

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

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#Id: 9446

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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

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#Id: 9447

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Large family of cytokines:

Interleukins

Interferons

Growth hormone

Prolactin

G-CSF

Thrombopoietin

Erythropoietin

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#Id: 9448

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Receptor Homodimerization 

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

TLS Online TPP Program

#Id: 9450

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Receptor hetero-dimerization or hetero-oligomerization 

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

TLS Online TPP Program

#Id: 9451

#XL - T Zoology

The extracellular domain of cytokine receptors are constructed of two subdomains, each contains seven conserved β strands folded together