1V18

The crystal structure of beta-catenin armadillo repeat complexed with a phosphorylated APC 20mer repeat.

Summary for 1V18

• Entry DOI: 10.2210/pdb1v18/pdb
• Related: 1DEB 1DOW 1EMU 1I7W 1I7X 1JPP 1M1E 1M5I 2BCT 3BCT
• Descriptor: BETA-CATENIN, ADENOMATOUS POLYPOSIS COLI (3 entities in total)
• Functional Keywords: signaling protein, signalling complex, wnt signal, beta-catenin degradation complex, cell adhesion, transcription, transcription regulation
• Biological source: MUS MUSCULUS (MOUSE); More
• Cellular location: Cytoplasm: Q02248; Cell junction, adherens junction: P25054
• Total number of polymer chains: 2
• Total formula weight: 64258.73

Authors

Ha, N.-C.,Weis, W.I. (deposition date: 2004-04-09, release date: 2005-01-12, Last modification date: 2024-11-06)

Primary citation

Ha, N.-C.,Tonozuka, T.,Stamos, J.L.,Weis, W.I.
Mechanism of Phosphorylation-Dependent Binding of Apc to Beta-Catenin and its Role in Beta-Catenin Degradation
Mol.Cell, 15:511-, 2004

PubMed Abstract: The transcriptional coactivator beta-catenin mediates Wnt growth factor signaling. In the absence of a Wnt signal, casein kinase 1 (CK1) and glycogen synthase kinase-3beta (GSK-3beta) phosphorylate cytosolic beta-catenin, thereby flagging it for recognition and destruction by the ubiquitin/proteosome machinery. Phosphorylation occurs in a multiprotein complex that includes the kinases, beta-catenin, axin, and the Adenomatous Polyposis Coli (APC) protein. The role of APC in this process is poorly understood. CK1epsilon and GSK-3beta phosphorylate APC, which increases its affinity for beta-catenin. Crystal structures of phosphorylated and nonphosphorylated APC bound to beta-catenin reveal a phosphorylation-dependent binding motif generated by mutual priming of CK1 and GSK-3beta substrate sequences. Axin is shown to act as a scaffold for substrate phosphorylation by these kinases. Phosphorylated APC and axin bind to the same surface of, and compete directly for, beta-catenin. The structural and biochemical data suggest a novel model for how APC functions in beta-catenin degradation.

PubMed: 15327768
DOI: 10.1016/J.MOLCEL.2004.08.010

Experimental method

X-RAY DIFFRACTION (2.1 Å)