Figure 3Protein levels of the validated SPPL2c substrates VAPA (A) were reduced using specific siRNAs. Non-targeting control siRNA (Ctr) served as negative control and overexpression of SPPL2c WT was used as a positive control. Non-transfected cells (-) or stably transfected but non-induced SPPL2c wt cells (n/i) served as additional controls for antibody specificity. Processing and maturation of ectopically expressed GnT-V and maturation of endogenous SPPL2a were monitored by Western Blotting. None of the substrates' knock down fully recapitulated the effect on GnT-V or on endogenous glycoproteins observed in SPPL2c overexpressing cells. Calnexin served as loading control and ectopic expression of SPPL2c WT and SPPL2c D/A was confirmed using a SPPL2c specific antibody.Protein levels of the validated SPPL2c substrates VAPB (B) were reduced using specific siRNAs. Non-targeting control siRNA (Ctr) served as negative control and overexpression of SPPL2c WT was used as a positive control. Non-transfected cells (-) or stably transfected but non-induced SPPL2c wt cells (n/i) served as additional controls for antibody specificity. Processing and maturation of ectopically expressed GnT-V and maturation of endogenous SPPL2a were monitored by Western Blotting. None of the substrates' knock down fully recapitulated the effect on GnT-V or on endogenous glycoproteins observed in SPPL2c overexpressing cells. Calnexin served as loading control and ectopic expression of SPPL2c WT and SPPL2c D/A was confirmed using a SPPL2c specific antibody.Protein levels of the validated SPPL2c substrates VAMP8 (C) were reduced using specific siRNAs. Non-targeting control siRNA (Ctr) served as negative control and overexpression of SPPL2c WT was used as a positive control. Non-transfected cells (-) or stably transfected but non-induced SPPL2c wt cells (n/i) served as additional controls for antibody specificity. Processing and maturation of ectopically expressed GnT-V and maturation of endogenous SPPL2a were monitored by Western Blotting. None of the substrates' knock down fully recapitulated the effect on GnT-V or on endogenous glycoproteins observed in SPPL2c overexpressing cells. Calnexin served as loading control and ectopic expression of SPPL2c WT and SPPL2c D/A was confirmed using a SPPL2c specific antibody.Protein levels of the validated SPPL2c substrates Syntaxin 8 (Stx8) (D) were reduced using specific siRNAs. Non-targeting control siRNA (Ctr) served as negative control and overexpression of SPPL2c WT was used as a positive control. Non-transfected cells (-) or stably transfected but non-induced SPPL2c wt cells (n/i) served as additional controls for antibody specificity. Processing and maturation of ectopically expressed GnT-V and maturation of endogenous SPPL2a were monitored by Western Blotting. None of the substrates' knock down fully recapitulated the effect on GnT-V or on endogenous glycoproteins observed in SPPL2c overexpressing cells. Calnexin served as loading control and ectopic expression of SPPL2c WT and SPPL2c D/A was confirmed using a SPPL2c specific antibody.Protein levels of the validated SPPL2c substrates Syntaxin 18 (Stx18) (E) were reduced using specific siRNAs. Non-targeting control siRNA (Ctr) served as negative control and overexpression of SPPL2c WT was used as a positive control. Non-transfected cells (-) or stably transfected but non-induced SPPL2c wt cells (n/i) served as additional controls for antibody specificity. Processing and maturation of ectopically expressed GnT-V and maturation of endogenous SPPL2a were monitored by Western Blotting. None of the substrates' knock down fully recapitulated the effect on GnT-V or on endogenous glycoproteins observed in SPPL2c overexpressing cells. Calnexin served as loading control and ectopic expression of SPPL2c WT and SPPL2c D/A was confirmed using a SPPL2c specific antibody.Protein levels of the validated SPPL2c substrates Membrin (F) were reduced using specific siRNAs. Non-targeting control siRNA (Ctr) served as negative control and overexpression of SPPL2c WT was used as a positive control. Non-transfected cells (-) or stably transfected but non-induced SPPL2c wt cells (n/i) served as additional controls for antibody specificity. Processing and maturation of ectopically expressed GnT-V and maturation of endogenous SPPL2a were monitored by Western Blotting. None of the substrates' knock down fully recapitulated the effect on GnT-V or on endogenous glycoproteins observed in SPPL2c overexpressing cells. Calnexin served as loading control and ectopic expression of SPPL2c WT and SPPL2c D/A was confirmed using a SPPL2c specific antibody.