scholarly journals Multiple Domains Within the Cauliflower mosaic virus Gene VI Product Interact with the Full-Length Protein

2002 ◽  
Vol 15 (10) ◽  
pp. 1050-1057 ◽  
Author(s):  
Yongzhong Li ◽  
Scott M. Leisner
Keyword(s):  
Mosaic Virus ◽  
Systemic Infection ◽  
Full Length ◽  
Cauliflower Mosaic Virus ◽  
The Other ◽  
Multifunctional Protein ◽  
Viral Propagation ◽  
Self Association ◽  
Multiple Domains ◽  
Two Hybrid

The Cauliflower mosaic virus (CaMV) gene VI product (P6) is a multifunctional protein essential for viral propagation. It is likely that at least some of these functions require P6 self-association. The work described here was performed to confirm that P6 self-associates and to identify domains involved in this interaction. Yeast two-hybrid analyses indicated that full-length P6 self-associates and that this interaction is specific. Additional analyses indicated that at least four independent domains bind to full-length P6. When a central domain (termed domain D3) was removed, these interactions were abolished. However, this deleted P6 was able to bind to the full-length wild-type protein and to isolated domain D3. Viruses lacking domain D3 were incapable of producing a systemic infection. Isolated domain D3 was capable of binding to at least two of the other domains but was unable to self-associate. This suggests that domain D3 facilitates P6 self-association by binding to the other domains but not itself. The presence of multiple domains involved in P6 self-association may help explain the ability of this protein to form the intracellular inclusions characteristic of caulimoviruses.

scholarly journals Lower temperature influences Cauliflower mosaic virus systemic infection

2021 ◽  
Author(s):  
Roberto Alers-Velazquez ◽  
Sushant Khandekar ◽  
Clare Muller ◽  
Jennifer Boldt ◽  
Scott Leisner
Keyword(s):  
Nucleic Acid ◽  
Actin Cytoskeleton ◽  
Mosaic Virus ◽  
Virus Particle ◽  
Systemic Infection ◽  
Cauliflower Mosaic Virus ◽  
Particle Release ◽  
Systemic Symptoms ◽  
Lower Temperature ◽  
Temperature Exposure

AbstractLower temperatures delayed development of systemic symptoms by Cauliflower mosaic virus (CaMV) in two different plant hosts. However, lower temperature exposure increased CaMV nucleic acid levels in leaves of systemically-infected turnips. Furthermore, lower temperature altered the formation of aggregates formed by the CaMV major inclusion body (IB) protein, P6. Finally, lower temperature altered the architecture of the actin cytoskeleton. These data may suggest that lower temperatures alter the actin cytoskeleton, facilitating the formation of larger IBs that hold on to their internal virions more strongly than small ones, impairing virus particle release and causing a delay in systemic infection.

scholarly journals The Avirulence Domain of Cauliflower mosaic virus Transactivator/Viroplasmin Is a Determinant of Viral Virulence in Susceptible Hosts

2004 ◽  
Vol 17 (5) ◽  
pp. 475-483 ◽  
Author(s):  
Kappei Kobayashi ◽  
Thomas Hohn
Keyword(s):  
Mosaic Virus ◽  
Host Plants ◽  
Datura Stramonium ◽  
Cauliflower Mosaic Virus ◽  
Wild Type Virus ◽  
Wild Type ◽  
Multifunctional Protein ◽  
Viral Virulence ◽  
Host Defense Response ◽  
Solanaceous Plants

Cauliflower mosaic virus (CaMV) transactivator/viroplasmin (Tav) is a multifunctional protein essential for basic replication of CaMV. It also plays a role in viral pathogenesis in crucifer and solanaceous host plants. Deletion mutagenesis revealed that N- and C-terminal parts of Tav are not essential for CaMV replication in transfected protoplasts. Two deletion mutants having only minimal defects in basic replication were infectious in turnips but only with highly attenuated virulence. This was shown to be due to delayed virus spread within the inoculated leaves and to the upper leaves. Unlike the wild-type virus, the mutant viruses successfully spread locally without inducing a host defense response in inoculated Datura stramonium leaves, but did not spread systemically. These results provide the first evidence that a Tav domain required for avirulence function in solanaceous plants is not essential for CaMV infectivity but has a role in viral virulence in susceptible hosts.

scholarly journals Components of Arabidopsis Defense- and Ethylene-Signaling Pathways Regulate Susceptibility to Cauliflower mosaic virus by Restricting Long-Distance Movement

2007 ◽  
Vol 20 (6) ◽  
pp. 659-670 ◽  
Author(s):  
Andrew J. Love ◽  
Valérie Laval ◽  
Chiara Geri ◽  
Janet Laird ◽  
A. Deri Tomos ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Systemic Acquired Resistance ◽  
Fluorescent Protein ◽  
Acquired Resistance ◽  
Systemic Infection ◽  
Cauliflower Mosaic Virus ◽  
Virus Movement ◽  
Wild Type ◽  
Long Distance ◽  
Systemic Spread

We analyzed the susceptibility of Arabidopsis mutants with defects in salicylic acid (SA) and jasmonic acid (JA)/ethylene (ET) signaling to infection by Cauliflower mosaic virus (CaMV). Mutants cpr1-1 and cpr5-2, in which SA-dependent defense signaling is activated constitutively, were substantially more resistant than the wild type to systemic infection, implicating SA signaling in defense against CaMV. However, SA-deficient NahG, sid2-2, eds5-1, and pad4-1 did not show enhanced susceptibility. A cpr5 eds5 double mutant also was resistant, suggesting that resistance in cpr5 may function partially independently of SA. Treatment of cpr5 and cpr5 eds5, but not cpr1, with salicyl-hydroxamic acid, an inhibitor of alternative oxidase, partially restored susceptibility to wild-type levels. Mutants etr1-1, etr1-3, and ein2-1, and two mutants with lesions in ET/JA-mediated defense, eds4 and eds8, also showed reduced virus susceptibility, demonstrating that ET-dependent responses also play a role in susceptibility. We used a green fluorescent protein (GFP)-expressing CaMV recombinant to monitor virus movement. In mutants with reduced susceptibility, cpr1-1, cpr5-2, and etr1-1, CaMV-GFP formed local lesions similar to the wild type, but systemic spread was almost completely absent in cpr1 and cpr5 and was substantially reduced in etr1-1. Thus, mutations with enhanced systemic acquired resistance or compromised ET signaling show diminished long-distance virus movement.

scholarly journals Differential Induction of Symptoms in Arabidopsis by P6 of Cauliflower mosaic virus

2003 ◽  
Vol 16 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Weichang Yu ◽  
Jane Murfett ◽  
James E. Schoelz
Keyword(s):  
Transgenic Plants ◽  
Mosaic Virus ◽  
Systemic Infection ◽  
Cauliflower Mosaic Virus ◽  
Minor Role ◽  
Primary Role ◽  
Complementation Assay ◽  
Unusual Variant ◽  
A Minor

The gene VI protein (P6) of Cauliflower mosaic virus (CaMV) functions as a virulence factor in crucifers by eliciting chlorotic symptoms in infected plants. The ability to induce chlorosis has been associated previously with P6 through gene-swapping experiments between strains and through the development of transgenic plants that express P6. The primary role that has been identified for P6 in the CaMV infection cycle is to modify the host translation machinery to facilitate the translation of the polycistronic CaMV 35S RNA. This function for P6 has been designated as the translational transactivator (TAV) function. In the present study, we have characterized an unusual variant of P6, derived from CaMV strain D4, that does not induce chlorosis upon transformation into Arabidopsis thaliana. The level of D4 P6 produced in transgenic Arabidopsis line D4-2 was comparable to the amount found in transgenic plants homozygous for W260 and CM1841 P6, two versions of P6 that induce strong chlorotic symptoms and stunting in Arabidopsis. A complementation assay proved that P6 expressed in the D4-2 line was functional, as it could support the systemic infection of a CM1841 mutant that contained a lethal frame-shift mutation within gene VI. This complementation assay allowed us to separately assess the contribution of CM1841 gene VI to symptom development versus the contribution of other CM1841 genes. Furthermore, a previous study had shown that the TAV activity of D4 P6 was comparable to that of W260 P6. That comparative analysis of TAV function, coupled with the characterization of the D4-2 transgenic line in the present paper, indicates that the TAV function of P6 may play only a minor role in the development of chlorotic symptoms.

The Full-Length Product of Cauliflower Mosaic Virus Open Reading Frame Ill Is Associated with the Viral Particle

Virology ◽  
1994 ◽  
Vol 202 (2) ◽  
pp. 1043-1045 ◽  
Author(s):  
Sandrine Dautel ◽  
Thierry Guidasci ◽  
Martin Pique ◽  
Jean-Luc Mougeot ◽  
Genevieve Lebeurier ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Viral Particle ◽  
Full Length ◽  
Cauliflower Mosaic Virus ◽  
Open Reading Frame ◽  
Reading Frame

scholarly journals The Capsid Protein of Satellite Panicum Mosaic Virus Contributes to Systemic Invasion and Interacts with Its Helper Virus

2005 ◽  
Vol 79 (15) ◽  
pp. 9756-9764 ◽  
Author(s):  
Rustem T. Omarov ◽  
Dong Qi ◽  
Scholthof G. Karen-Beth
Keyword(s):  
Cell Wall ◽  
Mosaic Virus ◽  
Capsid Protein ◽  
Specific Interaction ◽  
Infected Plant ◽  
Foxtail Millet ◽  
Systemic Infection ◽  
Helper Virus ◽  
Full Length ◽  
Start Codon

ABSTRACT Satellite panicum mosaic virus (SPMV) depends on its helper Panicum mosaic virus (PMV) for replication and spread in host plants. The SPMV RNA encodes a 17-kDa capsid protein (CP) that is essential for formation of its 16-nm virions. The results of this study indicate that in addition to the expression of the full-length SPMV CP from the 5′-proximal AUG start codon, SPMV RNA also expresses a 9.4-kDa C-terminal protein from the third in-frame start codon. Differences in solubility between the full-length protein and its C-terminal product were observed. Subcellular fractionation of infected plant tissues showed that SPMV CP accumulates in the cytosol, cell wall-, and membrane-enriched fractions. However, the 9.4-kDa protein exclusively cofractionated with cell wall- and membrane-enriched fractions. Earlier studies revealed that the 5′-untranslated region (5′-UTR) from nucleotides 63 to 104 was associated with systemic infection in a host-specific manner in millet plants. This study shows that nucleotide deletions and insertions in the 5′-UTR plus simultaneous truncation of the N-terminal part of the CP impaired SPMV spread in foxtail millet, but not in proso millet plants. In contrast, the expression of the full-length version of SPMV CP efficiently compensated the negative effect of the 5′-UTR deletions in foxtail millet. Finally, immunoprecipitation assays revealed the presence of a specific interaction between the capsid proteins of SPMV and its helper virus (PMV). Our findings show that the SPMV CP has several biological functions, including facilitating efficient satellite virus infection and movement in millet plants.

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