Two homologous host proteins interact with potato virus X RNAs and CPs and affect viral replication and movement

Abstract

Because viruses encode only a small number of proteins, all steps of virus infection rely on specific interactions between viruses and hosts. We previously screened several Nicotiana benthamiana (Nb) proteins that interact with the stem-loop 1 (SL1) RNA structure located at the 5′ end of the potato virus X (PVX) genome. In this study, we characterized two of these proteins (NbCPIP2a and NbCPIP2b), which are homologous and are induced upon PVX infection. Electrophoretic mobility shift assay confirmed that both proteins bind to either SL1(+) or SL1(−) RNAs of PVX. The two proteins also interact with the PVX capsid protein (CP) in planta. Overexpression of NbCPIP2a positively regulated systemic movement of PVX in N. benthamiana, whereas NbCPIP2b overexpression did not affect systemic movement of PVX. Transient overexpression and silencing experiments demonstrated that NbCPIP2a and NbCPIP2b are positive regulators of PVX replication and that the effect on replication was greater for NbCPIP2a than for NbCPIP2b. Although these two host proteins are associated with plasma membranes, PVX infection did not affect their subcellular localization. Taken together, these results indicate that NbCPIP2a and NbCPIP2b specifically bind to PVX SL1 RNAs as well as to CP and enhance PVX replication and movement.

Sugarcane Streak Mosaic Virus P1 Attenuates Plant Antiviral Immunity and Enhances Potato Virus X Infection in Nicotiana benthamiana

“…To uncover the mechanism of the enhancing role of P1 SCSMV on PVX pathogenesis, we wanted to explain the mechanism from the perspective of the expression profile of the candidate interacting proteins of PVX-encoded proteins. Twenty-two candidate host proteins—including NbeEF1A (Eukaryotic translation elongation factor 1A) [ 34 ], NbeEF1Bβ1 (Plant translation elongation factor), NbeEF1Bβ2 [ 35 ], NbTIPs [ 36 ], NbFD1 (Ferredoxin 1) [ 37 ], NbREM1–NbREM4 [ 38 ], NbPlastocyanin [ 39 ], NbActins [ 40 ], NbPCIP1-1–NbPCIP1-3 [ 41 ], NbMPB2Cb-1, NbMPB2Cb-2 (TMV-MP30 binding protein 2C, MPB2C) [ 42 ], and NbCPIP1–NbCPIP4 (CP interacting proteins, CPIPs) [ 43 ]—were selected for further analyses of their expression and transcription levels in the presence and absence of P1 SCSMV in N. benthamiana .…”

“…PVX CP-interacting protein 1 (NbPCIP1 or NbCPIP2) are plant-specific proteins that play an important role as susceptibility factors for viral infections or affect viral replication and movement [ 41 , 43 ]. The qRT-PCR results showed that the expression levels of NbPCIP1-1 , NbCPIP1 , and NbPCIP1-2 were dramatically downregulated, while the expression levels of NbCPIP2 , NbCPIP3 , NbCPIP4 , and NbPCIP1-2 were not altered in chimeric PVX-P1 SCSMV -infected plants compared with PVX-GFP-infected plants ( Figure 7 H,J).…”

“…This result also seems to contradict published data that PVX infections induce expression of NbCPIP1 in plants [ 63 ]. The CPIPs were supposed to act as important susceptibility factors of PVX, possibly by recruiting heat shock protein 70 chaperones for viral assembly or cellular movement in Nicotiana tobacco [ 63 ], whereas the NbCPIP2a and NbCPIP2b interact directly with the viral RNA stem-loop structures and CPs in plants for enhancing viral genomic RNA replication [ 43 ]. However, the relative downregulation of the NbCPIP1 was compared with the chimeric PVX-GFP, not with mock plants.…”

In-silico comparative modeling and interaction studies of PRSV proteins - Accelerated towards dissection of structure based evolutionary divergence and functional interaction of virus within the host

“…CP protein of Rice dwarf virus (RDV) hinders the auxin signaling by targeting the OslAA10 protein of rice thereby resulted in enhanced severity of viral infection [49]. The two homologous protein of N. benthamiana interacts with the CP gene of invading PVX virus and interfere in its encapsidation and movement [50]. Another report revealed that Cucumber mosaic virus -cholrosis inducing strain interacts with choloroplastic ferredoxin I (Fd I) protein, whereas the green mosaic-inducing strain of CMV did not showed this interaction, which suggested that the protein interactions vary with the type of strain of the same virus [48].…”

Effect of Polyphenols Intake on Obesity-Induced Maternal Programming

“…Salvianolic acid A (SA) is another natural polyphenolic compound found in Radix Salvia miltiorrhiza , with well reported anti-oxidant and anti-inflammatory properties [ 78 ]. It has been shown that SA can also reverse the HFD-induced obesity [ 79 ]. Indeed, a study conducted with HFD-induced obese mice showed that SA supplementation exerts its anti-obesity effects by activation of WAT browning via the AMPK-SIRT1 pathway [ 80 ].…”