Mini protean 2 gel apparatus

Proteins were separated by SDS-PAGE with a 4 % (w/v) stacking gel and a 12 % (w/v) resolving gel in a Mini-Protean II gel apparatus (Bio-Rad).

Western blot studies were performed as previously reported with minor modifications (Garro et al., 2001 (link); López de Jesús et al., 2006 (link); Ruiz de Azúa et al. 2006 ). Briefly, known amounts of total protein from P1, P2, Cyt or N fractions were heated for 5 min at 60 °C in urea-denaturing buffer (20 mM Tris-HCl, pH 8.0, 12% glycerol, 12% urea, 5% dithiothreitol, 2% sodium dodecyl sulphate, 0.01% bromophenol blue) and resolved by electrophoresis in 5–12% gradient SDS-polyacrylamide gels (SDS-PAGE) using the Mini Protean II gel apparatus (Bio-Rad; Hercules, CA, USA). Proteins were transferred to polyvinylidene fluoride (PVDF) membranes (Amersham Biosciences, Piscataway, NJ, USA), using the Mini TransBlot transfer unit (Bio-Rad; Hercules, CA, USA) at 30 V constant overnight at 4 °C and processed for immunoblot analysis (see Supplementary Material and Methods for details).