Analysis of Protein Phosphatase-1-binding Proteins by Microcystin Affinity Chromatography

• Main Author: 何詠寧
• Other Authors: 黃憲斌
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/35737256510791756060

碩士 === 國立中正大學 === 分子生物研究所 === 90 === Abstract Protein phosphatase 1 (PP1) and 2A (PP2A) are the major eukaryotic serine/threonine protein phosphatases that play a critical role in regulation of diverse cellular functions. Both phosphatases are present in cell by association with the different regulatory subunits to form the various holoenzymes. Therefore, identification of PP1 or PP2A holoenzymes will extend our understanding of the important regulatory molecules that regulate cell signaling through control of serine/threonine dephosphorylation. Both phosphatases are also the target for inhibition by various toxins such as microcystin, nodularin, okadaic acid and calyculin. Microcystin, a powerful liver tumor promoter, interacts covalently with PP1 and PP2A. Thus, microcystin will be an excellent ligand for purification of PP1 and PP2A holoenzymes. In this study, I prepared an affinity column that used microcystin as a ligand. This column was capable of purifying the recombinant PP1 from crude E. coli cell lysate extract to more than 80% homogeneity. This approach could be used to systematically identify PP1 and PP2A holoenzymes for proteomic studies.