IndraLab

Statements


CTNNB1 phosphorylated on S45 is inactive. 6 / 6
6 |

"We show that a complex of axin and casein kinase i (cki) induces beta-catenin phosphorylation at a single site: serine 45 (s45)."

"However, ckiepsilon has been recently shown to interact with axin (sakanaka et al. 1999;rubinfeld et al. 2001), and it was proposed that this kinase mediates axin-induced apc phosphorylation, thereby stabilizing the -catenin degradation complex (rubinfeld et al. 2001). We have, therefore, evaluated cki as a candidate s45-kinase in several assays, both in vitro and in vivo."

"Specifically, ck1_ phosphorylates _-catenin at s45, which primes this n-terminal region for subsequent phosphorylations by gsk3 at t41, s37 and s33 [7]. These latter two phosphorylations are recognized by the e3-ligase component, _-trcp, for ultimate ubiquitylation and destruction by the proteosome"

"We showed that CCND1-CDK6 phosphorylates beta-catenin on serine 45 (S45). This phosphorylation creates a priming site for glycogen synthase kinase 3beta (GSK3beta) and is both necessary and sufficient to initiate the beta-catenin phosphorylation-degradation cascade."

"However, ck1epsilon has been recently shown to interact with axin (sakanaka et al. 1999;rubinfeld et al. 2001), and it was proposed that this kinase mediates axin-induced apc phosphorylation, thereby stabilizing the beta-catenin degradation complex (rubinfeld et al. 2001). We have, therefore, evaluated ck1epsilon as a candidate s45-kinase in several assays, both in vitro and in vivo."

"Using mass spectrometry and phosphopeptide-specific antibodies, we show that a complex of axin and casein kinase I (CKI) induces Beta-catenin phosphorylation at a single site: serine 45 (S45)."