Fig. 9.

Time course of Slo1_VEDEC and Slo1_QEERL removal from the cell surface. Endocytosis assays were carried out by using HEK293T cells heterologously expressing either Slo1_VEDEC or Slo1_QEERL. The expressed channels bear an Myc tag at the extracellular NH₂ terminus, which allowed surface Slo1 on the surface of intact cells to be labeled by anti-Myc at 4°C. Cells were then placed at 37°C for various times to allow trafficking to resume, at which time they were fixed. The amounts of anti-Myc remaining on the cell surface were determined by HRP-conjugated anti-mouse with colorimetric assays at OD₄₉₂. Data show the time course of OD₄₉₂ (Mean ± S.E.M.) from three different experiments. ■, Slo1_VEDEC; ●, Slo1_QEERL. Data are fitted with single-exponential decay functions with time constants of 15.1 ± 0.9 (for Slo1_QEERL) and 14.4 ± 3.4 min (for Slo1_VEDEC).