Signaling by Activin

Stable Identifier
R-HSA-1502540
Type
Pathway
Species
Homo sapiens
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Activin was initially discovered as an activator of follicle stimulating hormone in the pituitary gland. It has since been shown to be an important participant in the differentiation of embryonic cells into mesodermal and endodermal layers. Activin binds the Activin receptor and triggers downstream events: phosphorylation of SMAD2 and SMAD3 followed by activation of gene expression (reviewed in Attisano et al. 1996, Willis et al. 1996, Chen et al. 2006, Hinck 2012). Activins are dimers comprising activin A (INHBA:INHBA), activin AB (INHBA:INHBB), and activin B (INHBB:INHBB). Activin first binds the type II receptor (ACVR2A, ACVR2B) and this complex then interacts with the type I receptor (ACVR1B, ACVR1C) (Attisano et al. 1996). The type II receptor phosphorylates the type I receptor and then the phosphorylated type I receptor phosphorylates SMAD2 and SMAD3. Dimers of phosphorylated SMAD2/3 bind SMAD4 and the resulting ternary complex enters the nucleus and activates target genes.

Literature References
PubMed ID Title Journal Year
8721982 Formation and activation by phosphorylation of activin receptor complexes

Willis, SA, Zimmerman, CM, Li, LI, Mathews, LS

Mol Endocrinol 1996
22651914 Structural studies of the TGF-?s and their receptors - insights into evolution of the TGF-? superfamily

Hinck, AP

FEBS Lett. 2012
16636301 Activin signaling and its role in regulation of cell proliferation, apoptosis, and carcinogenesis

Chen, YG, Wang, Q, Lin, SL, Chang, CD, Chuang, J, Chung, J, Ying, SY

Exp. Biol. Med. (Maywood) 2006
8622651 Activation of signalling by the activin receptor complex

Attisano, L, Wrana, JL, Montalvo, E, Massague, J

Mol Cell Biol 1996
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