TGF beta signaling pathway

The TGF beta superfamily of ligands

Bone morphogenetic protein

Bone morphogenetic protein

BMP-7 see Student Projects for UMass Chemistry 423 Spring 2012-4.

Bone morphogenetic protein 9

Bone morphogenetic protein 3D structures

Growth differentiation factor

Growth differentiation factor includes mentioned above Bone morphogenetic protein 9

Group:MUZIC:Myostatin

Activin

Activin

Activin A or inhibitin β chain A (ActA) is a member of the TGF-β superfamily that inhibits the proliferation of breast cancer cells. Activin interacts with activin receptors to induce phosphorylation of intracellular signalling molecules which regulate the transcription of many genes in a cell- and tissue-specific manner^[1].

TGF-beta receptor

TGF-β receptors (Transforming Growth Factor) (TGFR) are serine/threonine kinase receptors. They are involved in paracrine signaling and are found in many types of tissue. TGF-β ligands include bone morphogenetic proteins, growth and initiation factors, anti-Mullerian hormone, activin, nodal TGF-β^[2]. There are 3 types of TGFR:

• TGFR I forms heteromeric complex with TGFR II when it is bound to TGF-β. The complex transduces the TGF-β signal from the cell surface to the cytoplasm by phosphorylating proteins which regulate the transcription of genes related to cell proliferation. TGFR I has high affinity for TGF-β1 and low affinity for TGF-β2.
  
• TGFR II is a tumor suppressor transmembrane protein. TGFR II has high affinity for TGF-β1 and low affinity for TGF-β2.
  
• TGFR III is a cell-surface chondroitin sulfate / heparin sulfate proteoglycan. It acts as a reservoir of ligand for TGFRs. TGFR III has high affinity for TGF-β1, TGF-β2 and TGF-β1.2.

SMAD phosphorylation

There are five receptor regulated SMADs: SMAD1, SMAD2, SMAD3, SMAD5, and SMAD9 (sometimes referred to as SMAD8). There are essentially two intracellular pathways involving these R-SMADs. TGFβs, Activins, Nodals and some GDFs are mediated by SMAD2 and SMAD3, while BMPs, AMH and a few GDFs are mediated by SMAD1, SMAD5 and SMAD9.