7)

7). from either the PIV5 or Nipah disease nucleocapsid protein C-terminal ends are adequate to direct packaging of a foreign protein, luciferase, into budding VLPs. Mumps disease NP protein harbors DWD in place of the DLD sequence found in PIV5 NP protein, and consequently, PIV5 NP protein is definitely incompatible with mumps disease M protein. A single amino acid switch transforming DLD to DWD within PIV5 NP protein induced compatibility between these proteins and allowed efficient production of mumps VLPs. Our data suggest a model in which paramyxoviruses share an overall common strategy for directing M-NP relationships but with important variations contained within DLD-like sequences that play important roles in defining M/NP protein compatibilities. IMPORTANCE Paramyxoviruses are responsible for a wide range of diseases that impact both humans and animals. Paramyxovirus pathogens include measles disease, mumps disease, human being respiratory syncytial disease, and the zoonotic paramyxoviruses Nipah disease and Hendra disease. Infectivity of paramyxovirus Rabbit Polyclonal to HSD11B1 particles depends on matrix-nucleocapsid protein Hesperidin relationships which enable efficient packaging of encapsidated viral RNA genomes into budding virions. In this study, we Hesperidin have defined regions near the C-terminal ends of paramyxovirus nucleocapsid proteins that are important for matrix protein interaction and that are adequate to direct a foreign protein into budding particles. These results advance our basic understanding of paramyxovirus genome packaging relationships and also have implications for the potential use of virus-like particles as protein delivery tools. Intro The paramyxoviruses comprise a group of enveloped viruses that harbor nonsegmented, negative-sense RNA genomes (1). Included among the paramyxoviruses are a quantity of human being and animal pathogens, including measles disease, mumps disease, Nipah disease, respiratory syncytial disease (RSV), and Newcastle disease disease (NDV). Paramyxovirus infections are spread via particles which bud from plasma membranes of infected cells. Formation of these particles is driven from the viral matrix (M) proteins which can self-assemble to form ordered yet flexible arrays (2, 3) that likely play key tasks in generating the membrane curvature required for budding. M proteins also organize the particle assembly process by interacting with the viral glycoproteins via their cytoplasmic tails and also with the viral ribonucleoprotein (vRNP) complexes via the nucleocapsid (N or NP) proteins (examined in referrals 4 and 5). These relationships bring together and concentrate all the viral structural parts onto specific sites underlying infected cell plasma membranes, enabling infectious virions to consequently bud from these locations. For many paramyxoviruses, manifestation of M protein in the absence of some other viral parts is sufficient to induce the assembly and launch of virus-like particles (VLPs) from transfected cells. M proteins of Sendai disease (6, 7), measles disease (8, 9), Nipah disease (10, 11), Hendra disease (12), Newcastle disease disease (13), and human being parainfluenza disease 1 (HPIV1) (14) are all capable of directing VLP production and launch from transfected cells when indicated alone. In these cases, additional viral parts, including the viral glycoproteins and the nucleocapsid-like constructions that form upon manifestation of paramyxovirus N/NP proteins, can be efficiently packaged into the VLPs if they are coexpressed along with the M proteins (4). For additional paramyxoviruses, including mumps disease (15) and parainfluenza disease 5 (PIV5) (16), the viral M proteins do not induce significant VLP production when expressed only in transfected cells. In these cases, coexpression of M proteins together with viral glycoproteins and NP proteins is necessary for VLP production to occur. Such an set up could in theory provide a benefit to viruses by preventing the launch of bare virions that lack vRNPs. Additional negative-strand RNA (nsRNA) viruses, including Ebolavirus (17) Hesperidin and Tacaribe disease (18), for which enhancements to VLP production were observed upon coexpression of the viral nucleocapsid proteins may use related strategies. Paramyxovirus N/NP proteins function to bind and encapsidate viral genomic and antigenomic RNAs, forming helical nucleocapsid constructions that serve as the themes Hesperidin for the viral polymerase (19). Encapsidation, which is definitely directed from the RNA-binding, N-terminal core regions of the N/NP proteins, also protects viral RNAs from RNase digestion and impairs acknowledgement of viral RNAs by sponsor innate immune reactions (1). Flexibility between domains of the N/NP constructions is thought to allow for demonstration of the RNA bases and access from the viral polymerase only when needed (20,C22). The C-terminal tail regions of paramyxovirus N/NP proteins are dispensable for RNA binding and instead function to direct relationships with a variety of viral and sponsor proteins, including viral M proteins (23,C25) and viral P proteins (26,C28), although P protein binding and polymerase docking can.