𝝅-Turn

Consists of 6 amino acids, generally termed as i, i + 1 , i + 2 i + 3 i + 4 and i + 5

H-bond is seen between i and i + 5 (First and sixth residue)

TLS Online TPP Program

#Id: 9346

#Unit 4. Cell Communication and Cell Signaling

The prodomains of TGF-β1 and TGF-β3 contain a RGD motif, that allows them to bind to integrins.

TLS Online TPP Program

#Id: 9347

#Unit 4. Cell Communication and Cell Signaling

During cell migration, a tensile force is generated which physically distorts the prodomain and frees the active TGF-β dimer, initiating TGF-β signaling.

TLS Online TPP Program

#Id: 9348

#Unit 4. Cell Communication and Cell Signaling

3 separate TGF-β receptor proteins participate in binding TGF-β and activating signaling:

RI, RII, and RIII

TLS Online TPP Program

#Id: 9350

#Unit 4. Cell Communication and Cell Signaling

RI and RII receptors are homodimeric proteins with serine/threonine kinases in their cytosolic domains. 

(RI and RII sufficient to serve as a functional hetero-tetrameric TGF-β receptor)

TLS Online TPP Program

#Id: 9351

#Unit 4. Cell Communication and Cell Signaling

RII exhibits constitutive kinase activity; means it is active even when not bound to TGF-β.

TLS Online TPP Program

#Id: 9352

#Unit 4. Cell Communication and Cell Signaling

RIII, also called β-glycan, is a cell-surface proteoglycan.