Additional file 1.

Golgi and post-Golgi proteins in head microsomes fractionated by density gradient centrifugation followed by two phase affinity partitioning at 5.7% PEG/Dextran. A - Fractionated microsomes prepared from heads and probed for the Golgi protein Lava lamp. Two isoforms of Lava lamp are detected (arrows) at ~170 kDa and ~315 kDa. On average Golgi membrane is heavier than the peak ER fractions as expected [16]); double headed arrow; see Figure 3), but some overlap is seen especially with the larger isoform which has a bimodal distribution. B - Fractionated microsomes prepared from heads and probed with anti-Horseradish Peroxidase (HRP). The epitopes recognized by anti-HRP depend on the presence of N-glycan core α1,3-linked fucose [46] and thus detects proteins in trans-Golgi and post-Golgi compartments. The prominent epitope at 42 kDa is thought to be our PM marker Nervana [28]. Trans- and post-Golgi proteins detected by anti-HRP extend from the Golgi fractions through to the lightest region of the gradient as seen with the fully glycosylated Nervana isoforms (see Figure 3A). C - Fractionation by two phase affinity partitioning following an initial density gradient fractionation and probed with anti-HRP. The most prominent band behaves the same way as Nervana (see Figure 6B) and probably is Nervana (see [28]). An overexposure of the final ConA eluate (ConA over) is included to show that other anti-HRP detectable proteins are also present in the PM fraction. Labeling: same as figure 3 for A and B and figure 4 for C. Loading: Equivalent amounts of all fractions were loaded.

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Khanna et al. BMC Genomics 2010 11:302   doi:10.1186/1471-2164-11-302