Membrane Association and Topology of Citrus Leprosis Virus C2 Movement and Capsid Proteins

Abstract

Although citrus leprosis disease has been known for more than a hundred years, one of its causal agents, citrus leprosis virus C2 (CiLV-C2), is poorly characterized. This study described the association of CiLV-C2 movement protein (MP) and capsid protein (p29) with biological membranes. Our findings obtained by computer predictions, chemical treatments after membrane fractionation, and biomolecular fluorescence complementation assays revealed that p29 is peripherally associated, while the MP is integrally bound to the cell membranes. Topological analyses revealed that both the p29 and MP expose their N- and C-termini to the cell cytoplasmic compartment. The implications of these results in the intracellular movement of the virus were discussed.

The capsid protein of citrus leprosis virus C shows a nuclear distribution and interacts with the nucleolar fibrillarin protein

“…Several key findings have been reported regarding the CP of cilevirus (p29), including: i) cytoplasmatic localization in association with the endoplasmic reticulum (ER), actin filaments, and plasmodesmata; ii) intracellular traffic utilizing the ER-actin network, potentially allowing p29 to interact peripherally with cell membranes; iii) capacity to interact with cognate viral factors and movement-related proteins from dichorhavirus species; and iv) RSS activity, indicating that p29 may act as part of cilevirus counter-defense mechanism ( Leastro et al., 2020a , 2020b , 2021a ; Leastro et al., 2021b , 2018 ).…”

Spontaneous Mutation in the Movement Protein of Citrus Leprosis Virus C2, in a Heterologous Virus Infection Context, Increases Cell-to-Cell Transport and Generates Fitness Advantage

“…Although CiLV-C is considered the most devastating virus infecting citrus orchards in American countries [15], this situation is different in Colombia, where CiLV-C2 is prevalent in citrus orchards [14,[16][17][18]. As reviewed by Leastro et al [19], CiLV-C2 RNA 1 and RNA 2 present a nucleotide identity of 58 and 50%, respectively, compared to the corresponding CiLV-C RNA sequence, and their MPs present 51% of amino acid sequence identity [16].…”