Skip to main content
. 2011 Oct 17;6(10):e26109. doi: 10.1371/journal.pone.0026109

Figure 2. Direct identification of protein components of the cHS4 insulator complex by iChIP-mass spectrometry.

Figure 2

(A) Identification of insulator-binding proteins. Upper panel: Proteins isolated by iChIP were subjected to SDS-PAGE followed by silver-staining. Enlarged images of bands specific to the FCNLD/cHS4-core cell line are shown in Figure S2. Lower panel: The protein bands were subjected to mass spectrometry (LC-MS/MS) and identified as p68/DDX5 (I) and Matrin-3 (II). MW: molecular weight. See Figure S3 for MS/MS data. (B) Detection of p68 and Matrin-3 by iChIP followed by immunoblot analysis with anti-p68 and anti-Matrin-3 Ab. (C) Interaction of Matrin-3 with cHS4-core region in vivo. Upper panel: The plasmid possessing 2 copies of the cHS4 insulator and 8× repeats of the LexA binding sequence was randomly integrated in the genome of Ba/F3 cells. Lower panel: Specific interaction of Matrin-3 with cHS4-core in vivo. ChIP assay with anti-Matrin-3 Ab was performed to detect Matrin-3 binding.