Files in this Data Supplement:
Fig. S1. Comparison of CD9 and mutant CD9 expression. (A) MOLT-4, K562 and RD cells stably expressing CD9 were lysed in 1% Triton X-100, proteins were resolved by SDS-PAGE, and then CD9 and GAPDH were detected using chemiluminescence. (B) Cell-surface CD9 and mutant CD9 expression was determined by flow cytometry, on MOLT-4, RD and K562 cells, using mAb MM2/57. (C) On U937 cells, cell-surface expression of control MHC1 and CD9 was determined using mAbs W6/32 and ALB6, respectively.
Fig. S2. CD9 mutation effects on cell spreading. Spreading of (A) K652 and (B) MOLT-4 cells was determined, after 1 and 3 hours, as in Fig. 3. (C) Spreading of RD cells was determined as in Fig. 3, and photographed after 2 hours. (D) RD cell spreading percent was determined as in Fig. 3B. (E) RD cell spreading deviation from round was determined as in Fig. 3C.
Fig. S3. CD9 and mutant CD9 effects on microvilli formation in HT1080 cells. (A) HT1080 cells were stained for CD9 (green), F-actin (red) and cell nuclei (blue) as in Figure 5. Microvilli-like structures are marked with arrows. Scale bar: 20 µm. (B) Enumeration of microvilli (greater than 5 µm) was completed using Scion Image software, with quantification for each cell type from 10 random photos, each containing multiple cells (counted by staining of nuclei). **P<0.01.
Fig. S4. Cell-surface EWI-2 expression is unaffected by CD9 mutation. Cell-surface expression of EWI-2, on K562 and RD cells, was assessed by flow cytometry, using rabbit anti-EWI-2 antibody.
