Isolation of Human Mitotic Protein Phosphatase Complexes: Identification of a Complex between Protein Phosphatase 1 and the RNA Helicase Ddx21
Figure 7
PP1 is a toposome interaction partner within the mitotic spindle proteome. A.
Immunoprecipitation of SRPK1 identifies toposome components and PP1. Mitotic spindles were isolated and MAPs separated as in Fig. S1–2. Diluted MAPs (IN) were subjected to immunoprecipitations with SRPK1 or control (mouse IgG) antibodies. Bound proteins were eluted by boiling in 1X sample buffer. Western blot analyses were performed with antibodies against indicated proteins. B. PP1α, γ are the preferred interaction partners for SRPK1. Experiments were carried out as in A, except for the use of antibodies against human PP1 isoforms or control antibodies (PIS rabbit IgGs).