Figure 7. Deletion of TM11 results in a non-functional transporter.

(A) Transport currents induced by nontransfected cells, SNAT2_WT- and SNAT2_{Del TM11}-expressing cells at 10 mM of alanine and MeAIB uptake by vector (pBK-CMV (Δ[1098–1300])), SNAT2_{Del C-ter} and SNAT2_WT in transiently transfected HEK293 cells. Transport of [¹⁴C]MeAIB (40 μM) was measured at 1 min in NaMes-containing buffer. (B) Voltage-dependence of transport currents induced by SNAT2_{Del TM11} in the presence of 10 mM of alanine in nontranfected cells (open circles), SNAT2_WT- (squares) and SNAT2_{Del TM11}-expressing cells (triangles). (C) Average current-voltage relationships of anion leak current in the presence of 10 mM of alanine among nontransfected cells (contol, open circles), SNAT2_WT- (squares) and SNAT2_{Del TM11}- expressing cells (triangles). (D) Anion leak currents induced by 140 mM of extracellular Na⁺. The open triangles (SNAT2_WT) and open circles (SNAT2_{Del TM11}) are the currents from original experiments before subtraction of the unspecific leak currents (open squares, control, nontransfected cells). The solid circles are the anion leak currents induced by SNAT2_{Del TM11} after subtracting the unspecific currents (open circles). The inset shows the truncation site.