Figure S2.

ELKS and its associated proteins and/or homologs are not necessary for LAMP1Δ-RUSH post-Golgi tubule fusion. (A) TIRF imaging of LAMP1Δ-RUSH (gray) cells expressing heterologous HALO-ELKS (red) mostly localized to fusion sites (blue arrowheads). From Video 10. Scale bar: 10 μm. (B) Cell-surface ratio quantification (flow cytometry) of LAMP1Δ-RUSH at the plasma membrane after stable ELKS KO and 35 min of biotin exposure. (C) Immunoblot confirming loss of ELKS in a stable LAMP1Δ-RUSH ELKS KO clonal cell line. (D) Cell-surface ratio quantification (flow cytometry) of LAMP1Δ-RUSH at the plasma membrane after transient ELKS KO and 35 min of biotin exposure. (E) Cell-surface ratio quantification (flow cytometry) of LAMP1Δ-RUSH at the plasma membrane after transient KO of known ELKS interaction partners and 35 min of biotin exposure. This experiment was carried out in a stable clonal ELKS KO cell line. (F) Cell-surface ratio quantification (flow cytometry) of LAMP1Δ-RUSH at the plasma membrane after transient KO of EXOC1, ELKS, and combined. Error bar = SD of at least three independent experimental repeats. Two-tailed t test was performed on data in B and D, and Tukey’s multiple comparisons test (HSD, FWER = 0.05) was performed on data in F. *P ≤ 0.05; ***P ≤ 0.001.