Component of the beta-catenin destruction complex required for regulating CTNNB1 levels through phosphorylation and ubiquitination, and modulating Wnt-signaling. Controls dorsoventral patterning via two opposing effects; down-regulates CTNNB1 to inhibit the Wnt signaling pathway and ventralize embryos, but also dorsalizes embryos by activating a Wnt-independent JNK signaling pathway. In Wnt signaling, probably facilitates the phosphorylation of CTNNB1 and APC by GSK3B. Likely to function as a tumor suppressor. Facilitates the phosphorylation of TP53 by HIPK2 upon ultraviolet irradiation. Enhances TGF-beta signaling by recruiting the RNF111 E3 ubiquitin ligase and promoting the degradation of inhibitory SMAD7. Also component of the AXIN1-HIPK2-TP53 complex which controls cell growth, apoptosis and development.
Specificity
Natural and recombinant Human Axin-1
Subcellular Location
Cytoplasm Nucleus Cell membrane MACF1 is required for its translocation to cell membrane (By similarity). On UV irradiation, translocates to the nucleus and colocalizes with DAAX.
Homodimer (By similarity). Component of the beta-catenin destruction complex, containing at least, CTNNB1, an axin and GSK3B, that regulates CTNNB1 protein levels through phosphorylation and ubiquitination. Interacts with CTNNB1 (via the armadillo repeats 2-7). Interacts with GSK3B; the interaction hyperphosphorylates CTNNB1 leading to its ubiquitination and destruction. Component of the AXIN1-HIPK2-TP53 complex. Interacts directly in the complex with TP53 and HIPK2. Interacts with DAXX; the interaction stimulates the interaction of DAXX with TP53, stimulates 'Ser-46' phosphorylation of TP53 and induces cell death on UV irradiation. Also binds APC, SMAD6, SMAD7 and RNF111. Interacts with DIXDC1; prevents interaction with MAP3K1. Interacts with MAP3K4. Interacts with ANKRD6 and AIDA (By similarity). Interacts with MDFI; the interaction decreases AXIN1-mediated JUN N-terminal kinase (JNK) activation. Interacts with MDFIC; the interaction inhibits beta-cateninin-mediated signaling and AXIN1-mediated JUN N-terminal kinase (JNK) activation. Interacts with LRP5 (via its phosphorylated PPPSP motifs); the interaction is stimulated by WNT1 and GSK3B and activates beta-catenin signaling. Interacts (via the C-terminal) with PPP1CA; the interaction dephosphorylates AXIN1 and regulates interaction with GSK3B. Interacts with PPP2CA; the interaction dephosphorylates AXIN1. Interacts with MACF1 (By similarity). Found in a complex composed of MACF1, APC, AXIN1, CTNNB1 and GSK3B.