The chloroplast ribosomal protein large subunit 1 interacts with viral polymerase and promotes virus infection

Abstract

Chloroplasts play an indispensable role in the arms race between plant viruses and hosts. Chloroplast proteins are often recruited by plant viruses to support viral replication and movement. However, the mechanism by which chloroplast proteins regulate potyvirus infection remains largely unknown. In this study, we observed that Nicotiana benthamiana ribosomal protein large subunit 1 (NbRPL1), a chloroplast ribosomal protein, localized to the chloroplasts via its N-terminal 61 amino acids (transit peptide), and interacted with tobacco vein banding mosaic virus (TVBMV) nuclear inclusion protein b (NIb), an RNA-dependent RNA polymerase. Upon TVBMV infection, NbRPL1 was recruited into the 6K2-induced viral replication complexes in chloroplasts. Silencing of NbRPL1 expression reduced TVBMV replication. NbRPL1 competed with NbBeclin1 to bind NIb, and reduced the NbBeclin1-mediated degradation of NIb. Therefore, our results suggest that NbRPL1 interacts with NIb in the chloroplasts, reduces NbBeclin1-mediated NIb degradation, and enhances TVBMV infection.

The potyviral protein 6K2 from Turnip mosaic virus increases plant resilience to drought

“…The 6K2 protein localizes to the chloroplasts of plant cells (Taiyun et al . 2010; Cheng et al . 2021) and several chloroplast proteins have be linked to increased drought resistance (Lim, LEE & JANG 2014; Nawaz, Lee, Park, Kim & Kang 2018); therefore, we decided to investigate plants expressing 6K2 in more detail.…”

Strawberry Vein Banding Virus Movement Protein P1 Interacts With Light-Harvesting Complex II Type 1 Like of Fragaria vesca to Promote Viral Infection

“…During viral infection, many proteins encoded by plant viruses can interact with chloroplast proteins and affect the course of disease development ( Bhat et al, 2013 ; Mathioudakis et al, 2013 ; Cheng et al, 2021 ). The replicase protein of TMV interacts with the chloroplast ATPase γ subunit AtpC to block ATP synthesis, decrease photosynthate accumulation, and aggravate viral symptoms ( Bhat et al, 2013 ).…”

“…The replicase protein of TMV interacts with the chloroplast ATPase γ subunit AtpC to block ATP synthesis, decrease photosynthate accumulation, and aggravate viral symptoms ( Bhat et al, 2013 ). The replicase protein of tobacco vein banding mosaic virus interacts with the chloroplast 50S ribosomal protein large submit 1 to promote the accumulation of viral replicase and improve viral replication ( Cheng et al, 2021 ). Pepino mosaic virus (PepMV) MP P26 interacts with tomato chloroplast catalase 1 (CAT1) to improve the activity of CAT1.…”

Genome-Wide Identification of GDSL-Type Esterase/Lipase Gene Family in Dasypyrum villosum L. Reveals That DvGELP53 Is Related to BSMV Infection

“…NbRPL1 (ribosomal protein large subunit 1) interacts with NIb (mosaic virus (TVBMV) nuclear inclusion protein) in the chloroplasts, enhancing TVBMV infection. After inoculating TVBMV-GFP in NbRPL1-silenced N. benthamiana plants, the green fluorescence and TVBMV CP cannot be detected in the systemic leaves of the NbRPL1-silenced plants, only in control plants [50]. The auxin/indole acetic acid (Aux/IAA) transcriptional regulators IAA18, IAA26 and IAA27 interact with the tobacco mosaic virus (TMV) 126/183-kDa replicase [51]; a study showed that TMV infection inhibits the nuclear localization of the Aux/IAA proteins, which correlates with enhanced TMV movement and spread in the phloem of older leaves [52].…”

“…The chloroplasts play an important role in plant-virus interaction, and chloroplast proteins were proved to be involved in several viral infection processes [50]. Chloroplast proteins such as glyceraldehyde 3-phosphate dehydrogenase subunit A (NbGAPDH-A) [56] and chloroplast phosphoglycerate kinase (chl-PGK) [57] are both proven to be involved in virus replication and movement.…”