Fig. 6
The SNX25 PX domain is recruited to the plasma membrane via PtdIns(4,5)P2 interaction. a GFP-tagged PX domains from human SNX25, SNX13, SNX14, and SNX19 were expressed in S. cerevisiae and their localization examined by confocal fluorescence microscopy. Using single PX domains, only SNX19 shows membrane recruitment to the PtdIns3P-enriched vacuole. White arrows indicate examples of the vacuolar recruitment of the SNX19 PX domain. b The tandem GFP-SNX25PX-PX construct is recruited to the plasma membrane in yeast. This localization is blocked by the K734A lipid-binding mutation of the tandem PX domains. GFP linear profiles were made using RGB Profiler (ImageJ), and span the yeast cell. c In yeast with the temperature sensitive mss4ts allele, plasma membrane recruitment of GFP-SNX25PX-PX is normal at the permissive temperature of 25 °C, but lost at the restrictive temperature of 37 °C. This demonstrates that membrane interactions requires the synthesis of PtdIns(4,5)P2 by the sole yeast PI4P 5-kinase Mss4p
