Ubiquitin-Conjugating Enzyme E2 E Inhibits the Accumulation of Rice Stripe Virus in Laodelphax striatellus (Fallén)

Abstract

The ubiquitin–proteasome system (UPS) is an essential protagonist in host–pathogen interactions. Among the three classes of enzymes in the UPS, ubiquitin-conjugating enzyme E2 plays a dual role in viral pathogenesis; however, the role of insect E2s in interactions with plant viruses is unclear. Twenty E2-encoding genes in Laodelphax striatellus, the small brown planthopper, were identified and classified into 17 groups by transcriptomic and phylogenetic analysis. Full-length cDNAs of four LstrE2s (LstrE2 A/E/G2/H) were obtained by rapid-amplification of cDNA ends (RACE-PCR) analysis. Expression of the four LstrE2s showed tissue- and development-specific patterns. RT-qPCR analyses revealed that Rice stripe viruse (RSV) infection increased the level of LstrE2 A/E/G2/H. Further study indicated that repression of LstrE2 E via RNAi caused significant increases in the expression of RSV coat protein mRNA and protein levels. These findings suggest that LstrE2 E inhibits RSV accumulation in the planthopper body. Understanding the function of LstrE2 E in RSV accumulation may ultimately result in the development of novel antiviral strategies.

The Bunyavirales: The Plant-Infecting Counterparts

“…Besides endonuclease and polymerase activity within tenuivirus RdRps, the RSV RdRp furthermore contains deubiquitination activity [ 79 ]. The biological significance of this activity for the virus infection cycle is unknown, although a recent study has shown that the accumulation of RSV in the planthopper is inhibited by ubiquitin-conjugating enzyme E2 [ 80 ].…”

Silencing suppressors of rice black‐streaked dwarf virus and rice stripe virus hijack the 26S proteasome of Laodelphax striatellus to facilitate virus accumulation and transmission

“…28 Ubiquitin-conjugating enzyme E2 E could inhibit RSV accumulation in the planthopper body. 29 Conversely, viruses have evolved many strategies to regulate UPS processes mostly by directly interfering with the expression of related genes or by directly interacting with UPS components to maintain appropriate viral protein levels for successful infection. 30,31 The 26S consists of a core particle (CP) and 19S regulatory particles (RPs).…”

“…found that UPS regulates the accumulation of Turnip yellow mosaic virus (TYMV) RNA‐dependent RNA polymerase (RdRp) during viral infection and therefore decreases viral replication 28 . Ubiquitin‐conjugating enzyme E2 E could inhibit RSV accumulation in the planthopper body 29 . Conversely, viruses have evolved many strategies to regulate UPS processes mostly by directly interfering with the expression of related genes or by directly interacting with UPS components to maintain appropriate viral protein levels for successful infection 30,31 …”

Molecular Characteristics of Scylla paramamosain Ubiquitin-Conjugating Enzyme E2 and Expression Analysis During Oogenesis

“…For ubiquitin enzymes, E2 contains a ubiquitin-conjugating (UBC) domain, spanning 140-200 amino acids in length, which mediates the interaction between E2 and E3 (Gao et al, 2017). In ubiquitination, E2 plays a key role in regulating the fate and function of target proteins (Li et al, 2020). E2 genes exist as a multigene family that has been identified in model organisms, including Saccharomyces cerevisiae (Seufert et al, 1990), Caenorhabditis elegans (Jones et al, 2002), Homo sapiens (Jiang and Beaudet, 2004), Arabidopsis thaliana (Kraft et al, 2005), and Drosophila melanogaster (Michelle et al, 2009;Nagy et al, 2012).…”