Fig. 3.

Use of affinity pull-downs and mass spectroscopy to identify Importin-5 and Importin-8 as proteins interacting with hPPIP5K2. Panel a shows SDS-PAGE analysis of pull-downs of FLAG-beta-galactosidase (lane a) and FLAG-hPPIP5K2 (lane c), with molecular weight markers (lane b); see the Methods Section for further details. The entire gel lanes (a and c) were divided into 24 equal sections, each of which were then digested, lyophilized, and resuspended in 40 μl of 0.1% formic acid, prior to analysis. Panel b shows that importin-5 was identified in 13 spectra from 7 unique peptides (red font) and a distinct summed MS/MS search score of 91.06, yielding 8.2% sequence coverage. Panel c shows that importin-8 was identified by 6 spectra from 5 unique peptides (red font) and a distinct summed MS/MS search score of 68.63 with 5.9% sequence coverage. The individual spectra are provided in Additional file 2: Figures S1 and S2