Identification and Characterization of Plant-Interacting Targets of Tomato Spotted Wilt Virus Silencing Suppressor

• Main Authors: Ying Zhai, Prabu Gnanasekaran, Hanu R. Pappu
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Pathogens
• Subjects: affinity purification; calmodulin; carbonic anhydrase; heat shock protein; importin; mass spectrometry
• Online Access: https://www.mdpi.com/2076-0817/10/1/27

Tomato spotted wilt virus (TSWV; species <i>Tomato spotted wilt orthotospovirus</i>) is an economically important plant virus that infects multiple horticultural crops on a global scale. TSWV encodes a non-structural protein NSs that acts as a suppressor of host RNA silencing machinery during infection. Despite extensive structural and functional analyses having been carried out on TSWV NSs, its protein-interacting targets in host plants are still largely unknown. Here, we systemically investigated NSs-interacting proteins in <i>Nicotiana benthamiana</i> via affinity purification and mass spectrometry (AP-MS) analysis. Forty-three TSWV NSs-interacting candidates were identified in <i>N. benthamiana</i>. Gene Ontology (GO) and protein–protein interaction (PPI) network analyses were carried out on their closest homologs in tobacco (<i>Nicotiana tabacum</i>), tomatoes (<i>Solanum lycopersicum</i>) and <i>Arabidopsis</i> (<i>Arabidopsis thaliana</i>). The results showed that NSs preferentially interacts with plant defense-related proteins such as calmodulin (CaM), importin, carbonic anhydrase and two heat shock proteins (HSPs): HSP70 and HSP90. As two major nodes in the PPI network, CaM and importin subunit α were selected for the further verification of their interactions with NSs via yeast two-hybrid (Y2H) screening. Our work suggests that the downstream signaling, transportation and/or metabolic pathways of host-NSs-interacting proteins may play critical roles in NSs-facilitated TSWV infection.