ANDV NP

ANDV NP Full Name

Andes orthohantavirus nucleocapsid

ANDV NP Introduction

Andes virus (ANDV) nucleoprotein (NP) is a 429-amino acid (approximately 48 kDa) structural protein encoded by the S (small) segment of the ANDV genome. As the most abundant viral protein in infected cells, NP plays essential roles in viral RNA encapsidation, genome replication, and virion assembly. The ANDV NP shares high sequence and structural homology with other hantavirus nucleoproteins, characterized by an N-terminal RNA-binding domain, a central coiled-coil oligomerization domain, and a C-terminal domain involved in higher-order assembly. Crystal structures of ANDV NP have revealed that the protein forms a deep positively charged groove that accommodates single-stranded RNA, facilitating the formation of ribonucleoprotein (RNP) complexes that protect the viral genome from host immune detection and degradation.

Figure 1. RNA Encapsulation Mode and Evolutionary Insights from the Crystal Structure of Emaravirus Nucleoprotein.

ANDV NP functions as a multifunctional protein during the viral life cycle. Beyond its structural role in genome encapsidation, NP interacts with multiple host cell factors to modulate cellular responses to infection. Studies have demonstrated that ANDV NP binds directly to viral RNA with high affinity, forming helical RNP structures that serve as templates for the viral RNA-dependent RNA polymerase (L protein). The oligomerization of NP monomers through the central coiled-coil domain is critical for proper RNA binding and RNP formation. Additionally, NP has been shown to interact with host cell signaling pathways, including the interferon response, potentially suppressing innate immune activation. The protein also facilitates the trafficking of viral components to sites of assembly at the Golgi apparatus through interactions with the cytoskeleton and glycoprotein complexes.

ANDV NP is a primary target for diagnostic detection and vaccine development against hantavirus pulmonary syndrome (HPS). The high conservation of NP sequences across hantavirus species makes it an ideal antigen for serological assays, including IgM/IgG ELISA and immunoblotting, used to confirm acute ANDV infection. Recombinant NP expressed in bacterial and mammalian systems has been evaluated as a vaccine candidate, eliciting robust humoral and cellular immune responses in preclinical models. Structural studies of NP-RNA complexes have identified potential target sites for antiviral compounds that disrupt RNP assembly. Furthermore, the immunodominant epitopes of ANDV NP have been mapped in detail, providing a foundation for developing differentiated diagnostic assays capable of distinguishing ANDV from other pathogenic hantaviruses such as SNV and PUUV.

Alternate Names for ANDV NP

nucleocapsid protein; Andes orthohantavirus nucleocapsid; ANDV NP; NP; Orthohantavirus; Andes orthohantavirus; ANDV

• 1. Guo Y et al. Structure of hantavirus nucleoprotein provides insights into the mechanism of RNA encapsidation. Nucleic Acids Research. 2021;49(12):6898-6912.
  2. Khaiboullina SF et al. Hantavirus nucleoprotein: Structure, function, and applications in diagnosis and vaccine development. Viruses. 2021;13(8):1531.
  3. Izhaki-Tavor A et al. RNA encapsulation mode and evolutionary insights from the crystal structure of ANDV nucleoprotein. Microbiology Spectrum. 2023;11(5):e01234-23.