Supplementary Figure 5: In vitro assay of purified SPHK1.
From: Coupling between endocytosis and sphingosine kinase 1 recruitment
a. Coomassie-stained SDS-PAGE showing purified SPHK1-GFP-FLAG. b, Sphingosine kinase assay. Autoradiography of a TLC plate showing that purified SPHK1 is catalytically active as it phosphorylates sphingosine to generate radiolabeled sphingosine-1-phosphate in vitro. As the two lanes shown in the image were from the same TLC plate but not adjacent to each other, a black splice mark was included to separate the two lanes. The full TLC plate from which the data are extracted is shown in Supplementary Fig. 7c. The presence of SPHK1 on the membrane bilayer does not change the relationship between tubule radius and tension in the membrane tethering assay. n = 6 (with SPHK1) and 9 (without SPHK) pulled tubules. Each tubule represents an independent experiment, and data from independent experiments are averaged. Error bars represent standard error of the mean.
