Fig. 3. RNA-binding activity of Stau2 dsRBDs. Full-length mouse Stau2 fused to MBP (FL) and different dsRBDs fused to GST (1 to 5) were expressed in bacteria. Crude protein extracts were resolved by SDS PAGE and transferred on nitrocellulose membranes. Filters were incubated with either [³²P]bicoid 3'UTR RNA (A) or anti-GST antibodies (B). MBP, overexpressed MBP protein; BSA, 5 µg BSA. (C) A schematic representation of the fusion proteins with a summary of their RNA-binding capacity. Black and grey boxes represent the major and minor RNA-binding domains, respectively, whereas white boxes represent regions with RNA-binding consensus sequence but lacking RNA-binding activity in vitro. The hatched box indicates the position of the region similar to the MAP1B microtubule-binding domain. Boxes with dotted lines represent the rearranged dsRBD5 domain.