In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

Ebolaviruses are non-segmented, negative-sense RNA viruses (NNSVs) within the order 19 Mononegavirales that possess the multifunctional virion protein 35 (VP35), a major determinant 20 of virulence and pathogenesis that is indispensable for viral replication and host innate immune 21 evasion. VP35 is functionally equivalent to the phosphoprotein (P) of other mononegaviruses 22 such as rhabdoviruses and paramyxoviruses. Phosphorylation of the P protein is universally 23 regarded as functionally important however, a regulatory role(s) of phosphorylation on VP35 24 function remains unexplored. Here, we identified a highly conserved Ser129 residue near the 25 homo-oligomerization coiled coil motif, which is essential for VP35 functions. Affinity-purification 26 MS followed by post-translational modification (PTM) analysis predicted phosphorylation of 27 Ser129. Co-immunoprecipitation, cross-linking, and biochemical characterization studies 28 revealed a moderately decreased capacity of VP35-S129A to oligomerize. Functional analysis 29 showed that Ser-to-Ala substitution of Ebola virus (EBOV) VP35 did not affect IFN inhibitory 30 activity but nearly abolished EBOV minigenome activity. Further coimmunoprecipitation studies 31 demonstrated a lost interaction between VP35-S129A and the amino terminus of the viral 32 polymerase but not between viral nucleoprotein (NP) or VP35-WT. Taken together, our findings 33 provide evidence that phosphorylation modulates VP35 function, supporting VP35 as a NNSV P 34 protein and providing a potentially valuable therapeutic target. 35 Importance 36 Ebola virus (EBOV) can cause severe disease in humans. The 2013-2016 West African 37 epidemic and the two recent outbreaks in the Democratic Republic of the Congo underscore the 38 urgent need for effective countermeasures, which remain lacking. A better understanding of 39 EBOV biology and the modulation of multifunctional viral proteins is desperately needed to 40 develop improved therapeutics. We provide evidence here that function of virion protein 35 41 (VP35) is modulated by phosphorylation of Ser129, a conserved residue among other 42 ebolavirus species. These findings shed light on EBOV biology and present a potential target for 43 broad acting anti-ebolavirus therapeutics. 44 45 46 47 48 49
Mutation of Ebola virus VP35 Ser129 uncouples interferon antagonist and replication functions