scholarly journals Functional analysis of the Cucumber mosaic virus 2b protein: pathogenicity and nuclear localization

2004 ◽  
Vol 85 (10) ◽  
pp. 3135-3147 ◽  
Author(s):  
Yongzeng Wang ◽  
Tzvi Tzfira ◽  
Victor Gaba ◽  
Vitaly Citovsky ◽  
Peter Palukaitis ◽  
...  
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Nuclear Localization ◽  
Zucchini Yellow Mosaic Virus ◽  
Yellow Mosaic Virus ◽  
Silencing Suppressor ◽  
Nuclear Localization Signals ◽  
Systemic Movement ◽  
2B Protein ◽  
Function Expression

The 2b protein encoded by Cucumber mosaic virus (CMV) has been shown to be a silencing suppressor and pathogenicity determinant in solanaceous hosts, but a movement determinant in cucumber. In addition, synergistic interactions between CMV and Zucchini yellow mosaic virus (ZYMV) have been described in several cucurbit species. Here, it was shown that deletion of the 2b gene from CMV prevented extensive systemic movement of the virus in zucchini squash, which could not be complemented by co-infection with ZYMV. Thus, ZYMV expressing a silencing suppressor with a different target could not complement the CMV 2b-specific movement function. Expression of the 2b protein from an attenuated ZYMV vector resulted in a synergistic response, largely restoring infection symptoms of wild-type ZYMV in several cucurbit species. Deletion or alteration of either of two nuclear localization signals (NLSs) did not affect nuclear localization in two assays, but did affect pathogenicity in several cucurbit species, whilst deletion of both NLSs led to loss of nuclear localization. The 2b protein interacted with an Arabidopsis thaliana karyopherin α protein (AtKAPα) in the yeast two-hybrid system, as did each of the two single NLS-deletion mutants. However, 2b protein containing a deletion of both NLSs was unable to interact with AtKAPα. These data suggest that the 2b protein localizes to the nucleus by using the karyopherin α-mediated system, but demonstrate that nuclear localization was insufficient for enhancement of the 2b-mediated pathogenic response in cucurbit hosts. Thus, the sequences corresponding to the two NLSs must have another role leading to pathogenicity enhancement.

scholarly journals Systemic movement of a movement-deficient strain of Cucumber mosaic virus in zucchini squash is facilitated by a cucurbit-infecting potyvirus

2002 ◽  
Vol 83 (12) ◽  
pp. 3173-3178 ◽  
Author(s):  
Seung Kook Choi ◽  
Ju Yeon Yoon ◽  
Ki Hyun Ryu ◽  
Jang Kyung Choi ◽  
Peter Palukaitis ◽  
...  
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Cucurbita Pepo ◽  
Zucchini Yellow Mosaic Virus ◽  
Yellow Mosaic Virus ◽  
Long Distance ◽  
Systemic Movement ◽  
Tissue Print ◽  
Long Distance Movement

Zucchini squash (Cucurbita pepo) is a systemic host for most strains of the cucumovirus Cucumber mosaic virus (CMV), although the long-distance movement of the M strain of CMV (M-CMV) is inhibited in some cultivars. However, co-infection of zucchini plants with M-CMV and the potyvirus Zucchini yellow mosaic virus strain A (ZYMV-A) allowed M-CMV to move systemically, as demonstrated by tissue-print analysis. These doubly infected plants exhibited severe synergism in pathology. Infection of zucchini squash by M-CMV and an attenuated strain of ZYMV (ZYMV-AG) showed a milder synergy in pathology, in which ZYMV-AG also facilitated the long-distance movement of M-CMV similar to that promoted by ZYMV-A. Variation in the extent of synergy in pathology by the two strains of ZYMV did not correlate with differences in levels of accumulation of either virus. Thus, the extent of synergy in pathology is at least in part independent of the resistance-neutralizing function of the potyvirus.

scholarly journals The Role of the Cucumber mosaic virus 2b Protein in Viral Movement and Symptom Induction

2009 ◽  
Vol 22 (6) ◽  
pp. 642-654 ◽  
Author(s):  
Mathew Lewsey ◽  
Monique Surette ◽  
Fiona C. Robertson ◽  
Heiko Ziebell ◽  
Sun Hee Choi ◽  
...  
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Nuclear Localization Signals ◽  
Systemic Movement ◽  
Terminal Domain ◽  
2B Protein ◽  
Important Symptom

The Cucumber mosaic virus (CMV) 2b protein is a counter-defense factor and symptom determinant. Conserved domains in the 2b protein sequence were mutated in the 2b gene of strain Fny-CMV. The effects of these mutations were assessed by infection of Nicotiana tabacum, N. benthamiana, and Arabidopsis thaliana (ecotype Col-0) with mutant viruses and by expression of mutant 2b transgenes in A. thaliana. We confirmed that two nuclear localization signals were required for symptom induction and found that the N-terminal domain was essential for symptom induction. The C-terminal domain and two serine residues within a putative phosphorylation domain modulated symptom severity. Further infection studies were conducted using Fny-CMVΔ2b, a mutant that cannot express the 2b protein and that induces no symptoms in N. tabacum, N. benthamiana, or A. thaliana ecotype Col-0. Surprisingly, in plants of A. thaliana ecotype C24, Fny-CMVΔ2b induced severe symptoms similar to those induced by the wild-type virus. However, C24 plants infected with the mutant virus recovered from disease while those infected with the wild-type virus did not. Expression of 2b transgenes from either Fny-CMV or from LS-CMV (a mild strain) in Col-0 plants enhanced systemic movement of Fny-CMVΔ2b and permitted symptom induction by Fny-CMVΔ2b. Taken together, the results indicate that the 2b protein itself is an important symptom determinant in certain hosts. However, they also suggest that the protein may somehow synergize symptom induction by other CMV-encoded factors.

scholarly journals First Report of Infection of Fallopia multiflora with cucumber mosaic virus and zucchini yellow mosaic virus

2018 ◽  
Vol 100 (2) ◽  
pp. 333-333 ◽  
Author(s):  
Nam-Yeon Kim ◽  
Hyo-Jeong Lee ◽  
Mi-Ri Park ◽  
Jin-Sung Hong ◽  
Rae-Dong Jeong
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Zucchini Yellow Mosaic Virus ◽  
Yellow Mosaic Virus ◽  
First Report

scholarly journals 449 Cucurbit Viruses in Southern Illinois

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 471B-471
Author(s):  
S. Alan Walters ◽  
Jeff D. Kindhart ◽  
Houston A. Hobbs ◽  
Darin M. Eastburn
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Virus Disease ◽  
Zucchini Yellow Mosaic Virus ◽  
Growing Season ◽  
Yellow Mosaic Virus ◽  
Watermelon Mosaic Virus ◽  
Southern Illinois ◽  
Growing Seasons ◽  
Transgenic Squash

Cucurbit viruses are a major hindrance to cucurbit production in southern Illinois, often rendering cucumber and summer squash fruit unmarketable. Specific viruses infecting cucurbits in the region need to be determined since this would enable growers to make better decisions on virus disease management. Leaf samples of various cucurbit vegetables that had symptoms of viral infection were collected from grower fields during the 1998 and 1999 growing seasons to determine the predominant cucurbit viruses present. Samples were assayed for the presence of five individual viruses: cucumber mosaic virus (CMV), papaya ringspot virus (PRSV, formerly watermelon mosaic virus-1), squash mosaic virus (SqMV), watermelon mosaic virus (WMV, formerly watermelon mosaic virus-2), and zucchini yellow mosaic virus (ZYMV). Results from the two years indicated that WMV was the most prevalent virus in southern Illinois. Cucumber mosaic virus was found both years, but only in a low percentage of samples collected each year. Two cucurbit viruses, PRSV and ZYMV, were each identified only in one sample during the 1998 growing season, and neither were found in any of the samples collected during 1999. Squash mosaic virus was not identified in any of the samples collected during 1998; however, for the 1999 growing season, SqMV was identified in 19% of the samples collected, primarily from those samples of transgenic squash that were showing symptoms of virus infection.

scholarly journals Coat proteins of Rice tungro bacilliform virus and Mungbean yellow mosaic virus contain multiple nuclear-localization signals and interact with importin α

2005 ◽  
Vol 86 (6) ◽  
pp. 1815-1826 ◽  
Author(s):  
O. Guerra-Peraza ◽  
D. Kirk ◽  
V. Seltzer ◽  
K. Veluthambi ◽  
A. C. Schmit ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Nuclear Localization ◽  
Nuclear Import ◽  
Fluorescent Protein ◽  
Yellow Mosaic Virus ◽  
Rice Tungro Bacilliform Virus ◽  
Coat Proteins ◽  
Nuclear Localization Signals ◽  
Mungbean Yellow Mosaic Virus

Transport of the viral genome into the nucleus is an obligatory step in the replication cycle of plant pararetro- and geminiviruses. In both these virus types, the multifunctional coat protein (CP) is thought to be involved in this process. Here, a green fluorescent protein tagging approach was used to demonstrate nuclear import of the CPs of Rice tungro bacilliform virus (RTBV) and Mungbean yellow mosaic virus - Vigna (MYMV) in Nicotiana plumbaginifolia protoplasts. In both cases, at least two nuclear localization signals (NLSs) were identified and characterized. The NLSs of RTBV CP are located within both N- and C-terminal regions (residues 479KRPK/497KRK and 744KRK/758RRK), and those of MYMV CP within the N-terminal part (residues 3KR and 41KRRR). The MYMV and RTBV CP NLSs resemble classic mono- and bipartite NLSs, respectively. However, the N-terminal MYMV CP NLS and both RTBV CP NLSs show peculiarities in the number and position of basic residues. In vitro pull-down assays revealed interaction of RTBV and MYMV CPs with the nuclear import factor importin α, suggesting that both CPs are imported into the nucleus via an importin α-dependent pathway. The possibility that this pathway could serve for docking of virions to the nucleus is discussed.

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