Poly(Gly) chains also adopt secondary conformations. 

In the solid state poly(Gly) has been shown to adopt two regular conformations designated I and II. 

State I has an extended conformation like a β strand whilst state II has three resides per turn and is similar to poly(Pro).

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

IL-2 receptor complex activates

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

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#Unit 4. Cell Communication and Cell Signaling

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

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#Id: 9471

#Unit 4. Cell Communication and Cell Signaling

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

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#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

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#Id: 9473

#Unit 4. Cell Communication and Cell Signaling

SHP1 a phosphotyrosine phosphatase, contains:

SH2 domain  & Phosphatase domain

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#Id: 9474

#Unit 4. Cell Communication and Cell Signaling

SHP1 

Binding of an SH2 domain to a phosphotyrosine in the activated receptor unmasks its phosphatase catalytic site