FIG. 5.

Jak2 interacts with and tyrosine phosphorylates NF1-C2 in the nucleus. (A) Subcellular extracts from HC11 cells transfected with a plasmid encoding GFP-NF1-C2 fusion protein were immunoprecipitated (IP) with either anti-GFP or anti-pY antibody and subsequently Western blotted (WB) with an anti-GFP antibody or an anti-NF1-C2 antibody as indicated. N, nuclear extract; C, cytoplasmic extract. (B) The blots containing extracts immunoprecipitated with anti-GFP were stripped and reincubated with anti-Jak2 antibody. (C) Nuclear extract from HC11 cells treated with tyrphostin AG490 for 4 h was subjected to Western blot analysis. The blot was incubated with the NF1-C2-specific antibody as well as with anti-HDAC-1 and anti-α-tubulin as indicated. The amount of α-tubulin was controlled to guarantee that the difference observed was not due to differences in nuclear/cytoplasmic contamination levels. IgG, immunoglobulin G.