Displacement affinity chromatography of protein phosphatase one (PP1) complexes

Greg B.G. Moorhead, Laura Trinkle-Mulcahy, Mhairi Nimick, Veerle De Wever, David G. Campbell, Robert Gourlay, Yun Wah Lam, Angus I. Lamond

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60 Citations (Scopus)


Background. Protein phosphatase one (PP1) is a ubiquitously expressed, highly conserved protein phosphatase that dephosphorylates target protein serine and threonine residues. PP1 is localized to its site of action by interacting with targeting or regulatory proteins, a majority of which contains a primary docking site referred to as the RVXF/W motif. Results. We demonstrate that a peptide based on the RVXF/W motif can effectively displace PP1 bound proteins from PP1 retained on the phosphatase affinity matrix microcystin-Sepharose. Subsequent co-immunoprecipitation experiments confirmed that each identified binding protein was either a direct PP1 interactor or was in a complex that contains PP1. Our results have linked PP1 to numerous new nuclear functions and proteins, including Ki-67, Rif-1, topoisomerase IIα, several nuclear helicases, NUP153 and the TRRAP complex. Conclusion. This modification of the microcystin-Sepharose technique offers an effective means of purifying novel PP1 regulatory subunits and associated proteins and provides a simple method to uncover a link between PP1 and additional cellular processes.

Original languageEnglish
Article number28
Number of pages10
JournalBMC Biochemistry
Issue number1
Publication statusPublished - 10 Nov 2008
Externally publishedYes

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