scholarly journals A Lysine Residue Essential for Geminivirus Replication Also Controls Nuclear Localization of the Tomato Yellow Leaf Curl Virus Rep Protein

2019 ◽  
Vol 93 (10) ◽  
Author(s):  
Francesca Maio ◽  
Manuel Arroyo-Mateos ◽  
Benjamin G. Bobay ◽  
Eduardo R. Bejarano ◽  
Marcel Prins ◽  
...  
Keyword(s):  
Dna Replication ◽  
Nuclear Localization ◽  
Nuclear Import ◽  
Tomato Yellow Leaf ◽  
Host Factors ◽  
Yellow Leaf ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Rep Protein ◽  
Leaf Curl Virus

ABSTRACTGeminiviruses are single-stranded DNA (ssDNA) viruses that infect a wide range of plants. To promote viral replication, geminiviruses manipulate the host cell cycle. The viral protein Rep is essential to reprogram the cell cycle and then initiate viral DNA replication by interacting with a plethora of nuclear host factors. Even though many protein domains of Rep have been characterized, little is known about its nuclear targeting. Here, we show that one conserved lysine in the N-terminal part of Rep is pivotal for nuclear localization of the Rep protein fromTomato yellow leaf curl virus(TYLCV), with two other lysines also contributing to its nuclear import. Previous work had identified that these residues are essential for Rep fromTomato golden mosaic virus(TGMV) to interact with the E2 SUMO-conjugating enzyme (SCE1). We here show that mutating these lysines leads to nuclear exclusion of TYLCV Rep without compromising its interaction with SCE1. Moreover, the ability of TYLCV Rep to promote viral DNA replication also depends on this highly conserved lysine independently of its role in nuclear import of Rep. Our data thus reveal that this lysine potentially has a broad role in geminivirus replication, but its role in nuclear import and SCE1 binding differs depending on the Rep protein examined.IMPORTANCENuclear activity of the replication initiator protein (Rep) of geminiviruses is essential for viral replication. We now define that one highly conserved lysine is important for nuclear import of Rep from three different begomoviruses. To our knowledge, this is the first time that nuclear localization has been mapped for any geminiviral Rep protein. Our data add another key function to this lysine residue, besides its roles in viral DNA replication and interaction with host factors, such as the SUMO E2-conjugating enzyme.

scholarly journals Cellular Cleavage and Polyadenylation Specificity Factor 6 (CPSF6) Mediates Nuclear Import of Human Bocavirus 1 NP1 Protein and Modulates Viral Capsid Protein Expression

2019 ◽  
Vol 94 (2) ◽  
Author(s):  
Xiaomei Wang ◽  
Peng Xu ◽  
Fang Cheng ◽  
Yi Li ◽  
Zekun Wang ◽  
...  
Keyword(s):  
Dna Replication ◽  
Capsid Protein ◽  
Nuclear Import ◽  
Nonstructural Protein ◽  
Human Bocavirus ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Specificity Factor ◽  
Tract Infections

ABSTRACT Human bocavirus 1 (HBoV1), which belongs to the genus Bocaparvovirus of the Parvoviridae family, causes acute respiratory tract infections in young children. In vitro, HBoV1 infects polarized primary human airway epithelium (HAE) cultured at an air-liquid interface (HAE-ALI). HBoV1 encodes a small nonstructural protein, nuclear protein 1 (NP1), that plays an essential role in the maturation of capsid protein (VP)-encoding mRNAs and viral DNA replication. In this study, we determined the broad interactome of NP1 using the proximity-dependent biotin identification (BioID) assay combined with mass spectrometry (MS). We confirmed that two host mRNA processing factors, DEAH-box helicase 15 (DHX15) and cleavage and polyadenylation specificity factor 6 (CPSF6; also known as CFIm68), a subunit of the cleavage factor Im complex (CFIm), interact with HBoV1 NP1 independently of any DNA or mRNAs. Knockdown of CPSF6 significantly decreased the expression of capsid protein but not that of DHX15. We further demonstrated that NP1 directly interacts with CPSF6 in vitro and colocalizes within the virus replication centers. Importantly, we revealed a novel role of CPSF6 in the nuclear import of NP1, in addition to the critical role of CPSF6 in NP1-facilitated maturation of VP-encoding mRNAs. Thus, our study suggests that CPSF6 interacts with NP1 to escort NP1 imported into the nucleus for its function in the modulation of viral mRNA processing and viral DNA replication. IMPORTANCE Human bocavirus 1 (HBoV1) is one of the significant pathogens causing acute respiratory tract infections in young children worldwide. HBoV1 encodes a small nonstructural protein (NP1) that plays an important role in the maturation of viral mRNAs encoding capsid proteins as well as in viral DNA replication. Here, we identified a critical host factor, CPSF6, that directly interacts with NP1, mediates the nuclear import of NP1, and plays a role in the maturation of capsid protein-encoding mRNAs in the nucleus. The identification of the direct interaction between viral NP1 and host CPSF6 provides new insights into the mechanism by which a viral small nonstructural protein facilitates the multiple regulation of viral gene expression and replication and reveals a novel target for potent antiviral drug development.

Nuclear import of the capsid protein of tomato yellow leaf curl virus (TYLCV) in plant and insect cells

1998 ◽  
Vol 13 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Talya Kunik ◽  
Karuppaiah Palanichelvam ◽  
Henryk Czosnek ◽  
Vitaly Citovsky ◽  
Yedidya Gafni
Keyword(s):  
Capsid Protein ◽  
Nuclear Import ◽  
Insect Cells ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Leaf Curl Virus ◽  
Leaf Curl

Baculovirus LEF-11 nuclear localization signal is important for viral DNA replication

2017 ◽  
Vol 238 ◽  
pp. 133-140 ◽  
Author(s):  
Tingting Chen ◽  
Zhanqi Dong ◽  
Nan Hu ◽  
Zhigang Hu ◽  
Feifan Dong ◽  
...  
Keyword(s):  
Dna Replication ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Localization Signal

scholarly journals Human CAR Gene Expression in Nonpermissive Hamster Cells Boosts Entry of Type 12 Adenovirions and Nuclear Import of Viral DNA

2008 ◽  
Vol 82 (8) ◽  
pp. 4159-4163 ◽  
Author(s):  
Norbert Hochstein ◽  
Dennis Webb ◽  
Marianna Hösel ◽  
Werner Seidel ◽  
Sabrina Auerochs ◽  
...  
Keyword(s):  
Dna Replication ◽  
Nuclear Import ◽  
Cytopathic Effect ◽  
Adenovirus Type ◽  
Velocity Sedimentation ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Coxsackie And Adenovirus Receptor ◽  
Zone Velocity ◽  
Adenovirus Receptor

ABSTRACT Adenovirus type 12 (Ad12) propagation in hamster BHK21 cells is blocked prior to viral DNA replication. The amounts of Ad12 DNA in the nuclei or cytoplasm of hamster cells are about 2 orders of magnitude (2 h postinfection [p.i.]) and 4 to 5 orders of magnitude (48 h p.i.) lower than in permissive human cells. Cell line BHK21-hCAR is transgenic for and expresses the human coxsackie- and adenovirus receptor (hCAR) gene. Nuclear uptake of Ad12 DNA in BHK21-hCAR cells is markedly increased compared to that in naïve BHK21 cells. Ad12 elicits a cytopathic effect in BHK21-hCAR cells but not in BHK21 cells. Quantitative PCR or [3H]thymidine labeling followed by zone velocity sedimentation fails to detect Ad12 DNA replication in BHK21 or BHK21-hCAR cells. Newly assembled Ad12 virions cannot be detected. Thus, the block in Ad12 DNA replication in hamster cells is not released by enhanced nuclear import of Ad12 DNA.

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