Geminiviruses encode additional small proteins with specific subcellular localizations and virulence function

• Published in: Nature communications Vol. 12; no. 1; p. 4278
• Main Authors: Gong, Pan, Tan, Huang, Zhao, Siwen, Li, Hao, Liu, Hui, Ma, Yu, Zhang, Xi, Rong, Junjie, Fu, Xing, Lozano-Durán, Rosa, Li, Fangfang, Zhou, Xueping
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.07.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 14/19; 38; 45; 45/77; 631/326/596/2555; 631/326/596/2557; 631/449/2169/597; 631/449/2661/2666; 82/80; Begomovirus - pathogenicity; Geminiviridae - genetics; Geminiviridae - pathogenicity; Genome, Viral - genetics; Genomes; Golgi apparatus; Host-Pathogen Interactions - genetics; Host-Pathogen Interactions - physiology; Humanities and Social Sciences; Infections; Leaf-curl; multidisciplinary; Nicotiana - ultrastructure; Open reading frames; Open Reading Frames - genetics; Plant diseases; Plant Diseases - virology; Plant virus diseases; Plant viruses; Proteins; RNA Interference - physiology; RNA-mediated interference; Science; Science (multidisciplinary); Tomatoes; Viral infections; Viral Proteins - genetics; Viral Proteins - metabolism; Virulence; Viruses; Yellow leaf
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-24617-4

Geminiviruses are plant viruses with limited coding capacity. Geminivirus-encoded proteins are traditionally identified by applying a 10-kDa arbitrary threshold; however, it is increasingly clear that small proteins play relevant roles in biological systems, which calls for the reconsideration of this criterion. Here, we show that geminiviral genomes contain additional ORFs. Using tomato yellow leaf curl virus, we demonstrate that some of these small ORFs are expressed during the infection, and that the encoded proteins display specific subcellular localizations. We prove that the largest of these additional ORFs, which we name V3, is required for full viral infection, and that the V3 protein localizes in the Golgi apparatus and functions as an RNA silencing suppressor. These results imply that the repertoire of geminiviral proteins can be expanded, and that getting a comprehensive overview of the molecular plant-geminivirus interactions will require the detailed study of small ORFs so far neglected. Geminiviruses are small plant-infecting viruses. Here the authors screen the geminivirus genome for small open reading frames that may have been previously overlooked and show that one encodes a protein named V3 that localizes to the Golgi and acts as an RNA silencing suppressor.