Design and expression of NC mutants used for the fine mapping of Stau1/NC interaction. (A) Schematic representation of Pr55Gag with emphasis on the sequence of NC and its two zinc fingers. Several point mutations were introduced in the basic region or in the zinc fingers of NC-p1-YFP fusion protein to generate four mutants. (B) 293T cells were transfected with YFP, NC-p1-YFP and mutated NC-p1-YFP expressors. 48 hours post-transfection, cell lysates were prepared and analyzed by Western blotting using anti (α)-GFP antibodies.