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Basic region of residues 228–231 of protein kinase CK1α is involved in its interaction with axin: Binding to axin does not affect the kinase activity
Author(s) -
Sobrado Pablo,
Jedlicki Ana,
Bustos Victor H.,
Allende Catherine C.,
Allende Jorge E.
Publication year - 2005
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.20350
Subject(s) - casein kinase 1 , wnt signaling pathway , phosphorylation , microbiology and biotechnology , casein kinase 2 , protein kinase a , chemistry , kinase , scaffold protein , biochemistry , biology , cyclin dependent kinase 2 , signal transduction
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 Danio 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.