Over-expression of Stau1-HA
lacking amino acids 26 to 37 does not stimulate VLP production. 293T cells were transfected with a Rev-independent Pr55Gag expressor and constant (A) or increasing (B) amounts of either Stau155-HA3 or Stau1ΔNt88-HA3-expressing plasmids. Twenty-four hours post-transfection, cells extracts and VLPs were prepared (see "Methods" section) and analyzed by Western blotting using anti (α)-Stau1, anti (α)-HA and anti (α)-CA antibodies. Anti (α)-calnexin antibodies were used as a loading control. *: Non-specific labelling. (C) Amounts of Pr55Gag in cell extracts and in VLP were quantitated using Quantity One (version 4.5) software (Bio-Rad) and plotted as a function of the amounts of transfected Stau155-HA3 and Stau1ΔNt88-HA3-expressors. (D) Cells were transfected as in (A) with two additional N-terminal Stau1 mutants. Cell extracts and VLPs were prepared and analyzed as in (A).