Essential regions of SRPK2 for binding with Cp.

(A) Domain organization of SRPK2 constructs used for the in vitro GST pull-down assay. SRPK2ΔN, SRPK2ΔNS1, and SRPK2ΔS1 represent different truncation constructs of SRPK2; SRPK2DM is a docking groove mutant with 4 critical amino acid residues mutated to alanine. (B) In vitro GST pull-down assay was performed using GST-tagged Cp and His-tagged SRPK2 constructs. Results were analyzed by SDS-PAGE. Spacer region and N-terminal proline-rich motif are dispensable to the binding between SRPK2 and Cp while the docking groove is significant to the binding of SRPK2 and Cp.

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