Identification of the human PMR1 mRNA endonuclease as an alternatively processed product of the gene for peroxidasin-like protein

The 57-kDa PXDNL binds to c-Src and is tyrosine phosphorylated. The line of Src-deficient cells used previously to characterize the interaction of xPMR1 with c-Src (Peng and Schoenberg 2007) was cotransfected with a plasmids expressing Flag–57-kDa PXDNL with a C-terminal biotinylated tag and empty vector (lanes 1,4), constitutively active c-Src (CA-Src; lanes 2,5), or a dominant-negative form of c-Src (DN-Src; lanes 3,6), and cytoplasmic extracts from each of the transfectants were recovered with streptavidin paramagnetic beads. Five percent of input (lanes 1–3) and 100% of bound material (lanes 4–6) was applied to a 10% SDS-PAGE gel and analyzed by Western blotting with antibodies to the Flag tag, to c-Src, and to phosphotyrosine (pTyr).