Table 4.

Functional effects on global protein metabolism of 24 h of SNAT2 silencing with siRNA in L6-G8C5 myoblastsa

Transfection BlankControl Scrambled siRNASilencing siRNA
SNAT2 Transporter Activity t = 24 h
    pmol MeAIB/mg protein per min227 ± 48249 ± 5663 ± 19b
    % of control value97 ± 1010024 ± 7b
Total protein t = 28 h
    μg/35-mm well316 ± 55284 ± 40203 ± 31
    % of control value106 ± 1510071 ± 5b
Protein synthesis rate t = 24 to 28 h
    nmol l-Phe/mg protein in 4 h9.1 ± 1.29.2 ± 1.28.2 ± 1.1
    % of control value99 ± 110088 ± 2b
Protein degradation rate t = 26 to 33 h
    log10%/h × 1037.3 ± 0.47.7 ± 0.47.4 ± 0.4
    % of control value94 ± 610097 ± 5
Intact protein leakage (cell damage indicator) t = 26 to 33 h
    % per h0.11 ± 0.020.14 ± 0.030.09 ± 0.01
    % of control value84 ± 6b10073 ± 6b
  • a Pooled data from three experiments are shown (with three replicate culture wells for each treatment). Cells were transfected with SNAT2 silencing siRNA or scrambled control siRNA as described in Materials and Methods. Transfection was followed by a 24-h incubation in DMEM + 10% FBS. All measurements were then made in parallel at the times indicated in MEM at pH 7.4 with 2% dialyzed FBS. The times (t) denote the time elapsed since removal of the transfection agent.

  • b P < 0.05 versus scrambled control siRNA.