Overlapping assembly and nuclear trafficking signals in the RSV Gag polyprotein. Schematic diagram showing the RSV Gag cleavage products, assembly domains, nuclear targeting sequences and host nuclear transport factors that bind to Gag. MA, matrix; CA, capsid; NC, nucleocapsid; PR, protease; imp11, importin-11; TNPO3, transportin 3; imp-α, importin-α; impβ, importin-β.