Abstract

Protein kinase CK1, also known as casein kinase 1, participates in the phosphorylation of β-catenin, which regulates the functioning of the Wnt signaling cascade involved in embryogenesis and carcinogenesis. β-catenin phosphorylation occurs in a multiprotein complex assembled on the scaffold protein axin. The interaction of CK1α from Dani rerio with mouse-axin has been studied using a pull-down assay that uses fragments of axin fused to glutathione S transferase, which is bound to glutathione sepharose beads. The results indicate that the three lysines present in the basic region of residues 228-231 of CK1α are necessary for the binding of CK1 to axin. Lysine 231 is particularly important in this interaction. In order to define the relevance of the axin-CK1α interaction, the effect of the presence of axin on the phosphorylating activity of CK1α was tested. It is also evident that the region of axin downstream of residues 503-562 is required for CK1α interaction. The binding of CK1α to axin fragment 292-681 does not facilitate the phosphorylation of β-catenin despite the fact that this axin fragment can also bind β-catenin. Binding of CK1α to axin is not required for the phosphorylation of axin itself and, likewise, axin does not affect the kinetic parameters of the CK1α towards casein or a specific peptide substrate. © 2004 Wiley-Liss, Inc.

Department(s)

Chemistry

Publication Status

Full Access

Keywords and Phrases

β-catenin; Casein kinase 1; Docking sites; Scaffold proteins; Wnt signaling

International Standard Serial Number (ISSN)

0730-2312

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Wiley, All rights reserved.

Publication Date

01 Feb 2005

PubMed ID

15565646

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