Fig. 4.

PI4KIIα interactome reveals its regulation of the CARTS complex. A Proteins biotinylated by BirA*-PI4KIIα or BirA*-PI4KIIIβ in MCF-7 cells were identified by mass spectrometry (LTQ-Orbitrap XL). B Gene ontology (GO) biological process analysis was performed to characterize these PI4KIIα proximate proteins. C RFP-PI4KIIα was cotransfected with GFP-Rab8 or Myc-PAUF into MCF-7 cells, and the nucleus (blue) or Myc-PAUF (green) were immunostained using DAPI or a Myc mouse monoclonal antibody, respectively. Scale bar, 2 μm. D, E Myc-PAUF was overexpressed in WT and PI4KIIα-knockout MCF-7 cells. After 30 h, cells were incubated in serum-free DMEM for another 8 h. Cell lysates and culture media were collected, PAUF and GAPDH were detected by Western blot (D), and the bands were analyzed using ImageJ (E). PI4KIIα expression levels were also detected by Western blot, with GAPDH as a control. The data are presented as the mean ± SD of three independent experiments, except for those from the LC–MS/MS experiments