New potential peptide therapeutics perturbing CK1?/?-tubulin interaction

Members of the CK1 family are highly conserved serine/threonine specific kinases being expressed in all eukaryotes. They are involved in many cellular processes and therefore tightly regulated. A central mechanism to modulate CK1 activity is via interaction with cellular proteins. CK1? interacts with ?-/?-tubulin and is involved in the regulation of microtubule dynamics. Therefore, it is important to identify the structural elements responsible for the interaction between these proteins. Using a peptide library covering the human CK1? amino acid sequence in SPR and ELISA analyses, we identified peptide 39 (P39), encompassing aa361-aa375 of CK1?, as a prominent binding partner of ?-tubulin. P39 decreases ?-tubulin phosphorylation by CK1? and reduces the thermodynamic stability of ?-tubulin in fluorescence thermal shift assays. Furthermore, P39 induces an inhibition of mitotic progression and a disruption of cells entering mitosis in CV-1 cells. Taken together our data provide valuable information regarding the interaction of CK1? and ?-tubulin and a novel approach for the development of pharmacological tools to inhibit proliferation of cancer cells.