Oligomerizes into helical capsid to encapsidate the viral genome, protecting it from nucleases and the cellular innate immune response. VP35 binds to and stabilizes monomeric NP, keeping it soluble. Upon virus replication, NP is recruited to bind cooperatively viral genomic RNA and VP35 is released. The encapsidated genomic RNA is termed the nucleocapsid and serves as template for transcription and replication. The nucleocapsid is helical with a pitch of 10.81 NP per turn and a diameter of about 22nm. Each NP binds to six nucleotides of viral genomic RNA, three being exposed to the solvant and three hidden into the nucleocapsid. Recruits also host PPP2R5C phosphatase to dephosphorylate VP30 and thereby promote viral transcription. Upon virion assembly and budding, NP binds to VP24 and possibly host STAU1. Homooligomer. Homomultimerizes to form the nucleocapsid. Binds to viral genomic RNA. Interacts with VP35 and VP30 to form the nucleocapsid. Interacts with host PPP2R5C; this interaction leads to VP30 dephosphorylation and viral transcription. Interacts with VP24; this interaction facilitates nucleocapsid assembly and genome packaging. Interacts with matrix protein VP40; this interaction allows recruitment of the nucleocapsid into progeny virions. Interacts with host STAU1. Interacts with host NXF1 (via RNA-binding domain); this interaction recruits NXF1 to the inclusion bodies were viral replication takes place, probably to export viral mRNA-NXF1 complexes from these sites. Interacts with host CCDC92; this interaction sequesters NP in the host cytoplasm. Comprizes a N-terminal arm involved in oligomerization, a NP core region involved in RNA binding, a disordered region follwoed by a C-terminal tail involved in protein-protein interactions. During oligomerization, NP N-terminal arm binds to a neighbor NP thereby displacing VP35 bound to monomeric NP. Phosphorylated and O-glycosylated by host. Acetylated by host EP300 in vitro. Belongs to the filoviruses nucleoprotein family.