Colorectal cancer (CRC) is one of the most common and deadly diseases in the world, for which we still do not know an effective treatment. A frequent cause of the disease are mutations in the gene for APC, a key protein of the ß-catenin destruction complex, which is an important component of the Wnt signaling pathway. The latter regulates the intracellular level of ß-catenin, which acts as a transcriptional co-activator of Wnt genes in the nucleus upon activation of the Wnt signaling pathway. Proper functioning of the ß-catenin destruction complex, which maintains the appropriate level of this transcriptional activator by degrading cytoplasmic ß-catenin, is essential for proper cell proliferation, abnormalities of which lead to the development of various cancers. To better understand the functioning of the destruction complex, it is necessary to characterize the proteins involved in the complex. For this purpose, we wanted to prepare and isolate recombinant human ß-catenin in fusion with fluorescent proteins at the N- and C-terminus, which would enable further studies of its role in the functioning of the complex and cancer progression. Due to the tendency of the protein to cleave during expression, we approached its preparation by a procedure that was optimized for the preparation of ß-catenin without fusions. We also expressed the protein in a double fusion for easier isolation of uncleaved products. This proved to be effective, as we were able to express and isolate the desired ß-catenin in fusion with fluorescent proteins sfGFP and mCherry. To confirm the effectiveness of the procedure, additional quantitative analyses should be performed. Before using the prepared ß-catenin for further research, it would be necessary to purify and concentrate the protein completely.
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