Fig. 3.

Coiled-coil formation is critical for paraspeckle targeting by DBHS proteins. (A) Observed coiled-coil (atomic model) and model of extended coiled-coil (cyan residues indicate hendecad repeat). (B) Sequence alignment of PSPC1, NONO, and SFPQ coiled coils; green arrows mark C termini of truncated PSPC1 proteins able to form paraspeckles; red arrows, those that cannot. (C) A schematic model for coiled-coil-mediated oligomerization of DBHS proteins. (D) YFP fusion proteins of PSPC1 proteins terminating after residue 337 colocalize with paraspeckles in HeLa cells; shorter proteins do not. (Scale bars: 5 μm.) (E) Wild-type endogenous NONO is coimmunoprecipitated by truncated YFP-PSPC1 proteins in an anti-GFP pull-down. Anti-GFP and anti-NONO Western blots.