A Look into Bunyavirales Genomes: Functions of Non-Structural (NS) Proteins

Abstract

In 2016, the Bunyavirales order was established by the International Committee on Taxonomy of Viruses (ICTV) to incorporate the increasing number of related viruses across 13 viral families. While diverse, four of the families (Peribunyaviridae, Nairoviridae, Hantaviridae, and Phenuiviridae) contain known human pathogens and share a similar tri-segmented, negative-sense RNA genomic organization. In addition to the nucleoprotein and envelope glycoproteins encoded by the small and medium segments, respectively, many of the viruses in these families also encode for non-structural (NS) NSs and NSm proteins. The NSs of Phenuiviridae is the most extensively studied as a host interferon antagonist, functioning through a variety of mechanisms seen throughout the other three families. In addition, functions impacting cellular apoptosis, chromatin organization, and transcriptional activities, to name a few, are possessed by NSs across the families. Peribunyaviridae, Nairoviridae, and Phenuiviridae also encode an NSm, although less extensively studied than NSs, that has roles in antagonizing immune responses, promoting viral assembly and infectivity, and even maintenance of infection in host mosquito vectors. Overall, the similar and divergent roles of NS proteins of these human pathogenic Bunyavirales are of particular interest in understanding disease progression, viral pathogenesis, and developing strategies for interventions and treatments.

Highly adaptive Phenuiviridae with biomedical importance in multiple fields

“…NSm interacts with the outer mitochondrial membrane [52]. NSm regulates the p38 mitogenactivated protein kinase stress response and has an anti-apoptotic role, which is important for the infectivity of the phenuiviruses in dipteran insects [53]. For many phenuiviruses, the viral L and M segments are in the negative sense, while the viral S segment is in double senses for encoding proteins (Figure 2).…”

“…Some dipteran‐borne phenuiviruses (e.g., RVFV) encode another nonstructural protein, NSm, before the coding region of Gn in the M segment. NSm interacts with the outer mitochondrial membrane, regulates the p38 mitogen‐activated protein kinase stress response, and has an antiapoptotic role, which is important for the viral infectivity in dipteran insects 38,39 …”

“…NSm interacts with the outer mitochondrial membrane, regulates the p38 mitogen-activated protein kinase stress response, and has an antiapoptotic role, which is important for the viral infectivity in dipteran insects. 38,39 The small (S) segment encodes the nucleocapsid protein (N) that encapsulates the genomic RNA. RdRp, N, and genomic RNA constitute the viral ribonucleoproteins (RNPs).…”

Evcil ruminatlarda Kırım-Kongo Kanamalı Ateşi Virusu (KKKAV) enfeksiyonunun seroepidemiyolojik araştırması, Adana ili, Doğu Akdeniz bölgesi, Türkiye.

“…Crimean-Congo hemorrhagic fever virus (CCHF) is considered to be one of the most medically important and highly pathogenic tick-borne zoonoses affecting humans, first seen in Crimea in 1944 and later in Congo in 1956 (Appannanavar and Mishra, 2011;Leblebicioglu et al, 2016). CCHFV is a negative-sense singlestranded RNA (ssRNA) virus and depicted for Nairoviridae family of Bunyavirales order and is widely distributed around the world (Appannanavar and Mishra, 2011;Leventhal et al, 2021). More than 10000 patients have been reported since the first CCHFV cases in Turkey in 2002 (Aydın and Coşkun, 2019;Leblebicioglu et al, 2016;Yilmaz et al, 2009).…”

Genome-Wide Identification and Functions against Tomato Spotted Wilt Tospovirus of PR-10 in Solanum lycopersicum

“…M RNA is an antisense RNA that codes for the amino acid and carboxy-terminal location of the glycoprotein precursor (GnGc), which is required for virions to assemble, mature, and release into their host [14]. The viral nonstructural proteins (NSm), which are encoded by sense RNA, are the main promoters of TSWV infection [15]. S RNA also contains a double sense RNA, with antisense RNA encoding nucleocapsid proteins (N) and sense RNA encoding nonstructural proteins (NSs) [16]; both proteins have a crucial function in the TSWV infection cycle [17].…”