ROR1P808A is unable to associate with DOCK2, induce Rac1/2 activation, or enhance leukemia cell proliferation. (A) Schematic depicts the structure of ROR1 protein with different domains. (B) ΔPRD represents the truncated form of ROR1 without its P-rich region. (C) Amino acid sequences of the P-rich domain of ROR1. Asterisks indicate the P amino acid residues that had been substituted with A. (D) Immunoblot analysis of anti-ROR1 (cirmtuzumab) immune precipitates from lysates of MEC1-Ctrl, MEC1-ΔPRD, or MEC1-ROR1 cells, as indicated on the top. Membranes were probed with anti-ROR1 or anti-DOCK2 antibody, as indicated on the left. (E) Interaction of ROR1 with DOCK2 was confirmed by immunoblot analysis of anti-ROR1 (cirmtuzumab) immune precipitates from lysates of MEC1, MEC1-ΔPRD, MEC1-ROR1, or MEC1 cells transfected with each of the various mutated forms of ROR1, as indicated on the top (upper panel). In the lower panel is an immunoblot of the whole-cell lysates of the MEC1-Ctrl, MEC1-ΔPRD, MEC1-ROR1, or MEC1 cells transfected with each of the various mutated forms of ROR1, as indicated on the top, and probed with anti-DOCK2 antibody.
