Neither the PH-like domain nor the SMP domain is responsible for interacting with TMEM55B. (A and B) Representative images of a COS7 cell expressing either Tex2-ΔTM-ΔPH (green; A), or Tex2-ΔPH (green; B), along with Lamp1-mCh (blue) and Halo-TMEM55B (magenta) with insets. Yellow arrows indicate Tex2 enrichments at TMEM55B-positive LE/lys. (C) PIPs strip assay of purified Tex2-PH. Left: Coomassie blue staining of purified Tex2-PH; right: PIPs strip blots. (D) Representative images of a COS7 cell expressing Tex2-ΔSMP (green) and Lamp1-mCh (blue) and Halo-TMEM55B (magenta) with insets. Yellow arrows indicate Tex2 proteins enrichment at TMEM55B-positive LE/lys. (E) Representative images of a COS7 cell expressing Tex2-SMP alone (gray; left) or Tex2-SMP along with Lamp1-mCh (blue) and Halo-TMEM55B (magenta) with an inset (right). (F and G) Representative images of a COS7 cell expressing Tex2-1-474 (green; F) or Tex2-1-276 (green; G), along with Lamp1-mCh (blue) and Halo-TMEM55B (magenta) with insets. (H) Pearson’s correlation coefficient of either Tex2-ΔTM-ΔPH (10 cells), Tex2-ΔPH (10 cells), Tex2-ΔSMP (11 cells), Tex2-SMP (9 cells), Tex2-1-474 (9 cells), or Tex2-1-276 (11 cells) vs. Halo-TMEM55B in three independent assays. Ordinary one-way ANOVA with Tukey’s multiple comparisons test. Mean ± SD. Scale bar, 10 μm in the whole cell images and 2 μm in the insets in A, B, D, F, and G. Source data are available for this figure: SourceData FS4.