GSK3 Beta Interaction Protein (GSKIP)

GSKIP, which binds to GSK3 beta. GSKIP is a good GSK3 beta substrate, and both the full-length protein and a C-terminal fragment of GSKIP can block phosphorylation of primed and nonprimed substrates in different fashions. Similar to Axin GID(381-405) and FRATtide, synthesized GSKIPtide is also shown to compete with and/or block the phosphorylation of Axin and beta-catenin by GSK3 beta. overexpression of GSKIP induces beta-catenin accumulation in the cytoplasm and nucleus as visualized by immunofluorescence. A functional assay also demonstrates that GSKIP-transfected cells have a significant effect on the transactivity of Tcf-4. GSKIP as a naturally occurring protein that is homologous with the GSK3 beta interaction domain of Axin and is able to negatively regulate GSK3 beta of the Wnt signaling pathway.