What signaling pathway is beta catenin involved in?
What signaling pathway is beta catenin involved in?
Abstract. β-Catenin is involved both in cadherin-mediated intercellular adhesion and transcriptional coactivation downstream of the Wnt signaling pathway. Accumulation of β-catenin by inhibition or knockout of its negative regulator GSK3 is known to sustain pluripotency in conjunction with other factors.
What is beta catenin signaling?
Wnt/β-catenin signaling, a highly conserved pathway through evolution, regulates key cellular functions including proliferation, differentiation, migration, genetic stability, apoptosis, and stem cell renewal.
What happens when beta catenin is phosphorylated?
β-Catenin is phosphorylated on its N-terminus by GSK3 (shown in orange) and CKI (shown in orange). These phosphorylations target β-catenin for ubiquitination and subsequent proteasomal degradation. β-Catenin is also phosphorylated on the indicated sites by the diverse kinases PKA, AKT, and JNK2.
What activates the Wnt pathway?
The Wnt/β-catenin pathway is activated when a Wnt ligand binds to a seven-pass transmembrane Frizzled (Fz) receptor and its co-receptor, low-density lipoprotein receptor related protein 6 (LRP6) or its close relative LRP5.
How is beta-catenin activated?
The Wnt system is 1 of the well-known potent pathways, which activates nuclear β-catenin. In the absence of Wnt signal, free cytoplasmic β-catenin is phosphorylated by serine/threonine kinases, casein Kinase Iα (CKIα) and GSK3β in a large APC/axin scaffolding complex that targets β-catenin for degradation.
What is the role of beta-catenin?
Beta-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcription. In humans, the CTNNB1 protein is encoded by the CTNNB1 gene. It is a member of the catenin protein family and homologous to γ-catenin, also known as plakoglobin.
What is a destruction complex?
The destruction complex is likely a dynamic multiprotein assembly, but its core components include, in addition to β-catenin itself, the Ser/Thr kinases glycogen synthase kinase 3 (GSK-3) and casein kinase 1 (CK1), the scaffolding protein Axin, the adenomatous polyposis coli (APC) protein, and the E3-ubiquitin ligase β …
How is beta catenin activated?
Does Wnt stabilize beta catenin?
Wnts also stabilize β-catenin via inhibition of GSK-3β, but, in contrast to hypertrophic signaling, this is not believed to involve PKB-induced Ser-9 phosphorylation (16, 32).
What happens when there is too much beta-catenin?
We report here that overexpression of beta-catenin results in accumulation of p53, apparently through interference with its proteolytic degradation. This effect involves both Mdm2-dependent and -independent p53 degradation pathways, and is accompanied by augmented transcriptional activity of p53 in the affected cells.
Why is beta catenin called armadillo?
Examples of proteins that contain armadillo repeats include β-catenin, α-importin, plakoglobin, adenomatous polyposis coli (APC), and many others. The term armadillo derives from the historical name of the β-catenin gene in the fruitfly Drosophila where the armadillo repeat was first discovered.
What is beta catenin destruction complex?
If APC is not dephosphorylated in the complex, phosphorylated APC bound to β-catenin might leave the destruction complex together and only be separated at the proteasome.
