PARAMYXOVIRUS FUSION (F) PROTEIN AND HEMAGGLUTININ-NEURAMINIDASE (HN)PROTEIN INTERACTIONS - INTRACELLULAR RETENTION OF F AND HN DOES NOT AFFECT TRANSPORT OF THE HOMOTYPIC HN OR F PROTEIN

To investigate a possible intracellular coassociation of the paramyxov irus simian virus 5 (SV5) and human parainfluenza virus type 3 (HPIV-3 ) fusion (F) and hemagglutinin-neuraminidase (HN) glycoproteins in a l iving cell, without resorting to chemical crosslinking and antibody co immunoprecipitation, we tagged the cytoplasmic N-terminus of SV5 HN wi th a RRRRR motif and HPIV-3 HN with a RRR motif for endoplasmic reticu lum (ER) retention, In addition, we tagged the cytoplasmic C terminus of SV5 and HPIV-3 F with a KK motif. The RRR- or RRRRR-tagged HN molec ules were coexpressed in mammalian cells together with the homologous wt: F proteins, and the KK-tagged F molecules were coexpressed with th e homologous wt HN proteins, and in each case the transport of the wt F or HN molecules was investigated. The data suggest that an associati on of F and HN of sufficient affinity to alter the transport of the re porter molecule does not occur intracellularly in the ER or the Golgi apparatus. (C) 1997 Academic Press.