• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.106-106
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• 2002

• The Plant Pathology Journal
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• 제37권1호
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• pp.47-56
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• 2021

Plants protect against viruses through passive and active resistance mechanisms, and in most cases characterized thus far, natural recessive resistance to potyviruses has been mapped to mutations in the eukaryotic initiation factor eIF4E or eIF(iso)4E genes. Five eIF4E copies and three eIF(iso)4E copies were detected in Brassica rapa. The eIF4E and eIF(iso)4E genes could interact with turnip mosaic virus (TuMV) viral protein linked to the genome (VPg) to initiate virus translation. From the yeast two-hybrid system (Y2H) and bimolecular fluorescence complementation (BiFC) assays, the TuMV-CHN2/CHN3 VPgs could not interact with BraA.eIF4E.a/c or BraA.eIF(iso)4E.c, but they could interact with BraA.eIF(iso)4E.a in B. rapa. Further analysis indicated that the amino acid substitution L186F (nt T556C) in TuMV-UK1 VPg was important for the interaction networks between the TuMV VPg and eIF(iso)4E proteins. An interaction model of the BraA. eIF(iso)4E protein with TuMV VPg was constructed to infer the effect of the significant amino acids on the interaction of TuMV VPgs-eIF(iso)4Es, particularly whether the L186F in TuMV-UK1 VPg could change the structure of the TuMV-UK1 VPg protein, which may terminate the interaction of the BraA.eIF(iso)4E and TuMV VPg protein. This study provides new insights into the interactions between plant viruses and translation initiation factors to reveal the working of key amino acids.

• The Plant Pathology Journal
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• 제23권4호
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• pp.281-286
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• 2007

Interactions between viral proteins and host proteins are essential for virus replication. Especially, translation of viral genes completely depends on the host machinery. In potyviruses, interactions of genome-linked viral protein (VPg) with host translation factors including eIF4E, eIF(iso)4E, and poly(A)-binding protein (PABP) has previously been characterized. In this study, we investigated interactions between Soybean mosaic virus (SMV) viral proteins and host translation factors by yeast two-hybrid system. SMV VPg interacted with eIF4E, eIF(iso)4E, and PABP in yeast two-hybrid system, while SMV helper component proteinase (HC-pro) interacted with neither of those proteins. The interaction between SMV NIb and PABP was also detected. These results are consistent with those reported previously in other potyviruses. Interestingly, we found reproducible and specific interactions between SMV coat protein (CP) and PABP. Deletion analysis showed that the region of CP comprising amino acids 116 to 206 and the region of PABP comprising amino acids 520 to 580 are involved in CP/PABP interactions. Soybean library screening with SMV NIb by yeast two-hybrid assay also identified several soybean proteins including chlorophyll a/b binding preprotein, photo-system I-N subunit, ribulose 1,5-biphosphate carboxylase, ST-LSI protein, translation initiation factor 1, TIR-NBS type R protein, RNA binding protein, ubiquitin, and LRR protein kinase. Altogether, these results suggest that potyviral replicase may comprise a multi-protein complex with PABP, CP, and other host factors.

• 생명과학회지
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• 제7권4호
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• pp.392-401
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• 1997

폴리오바이러스는 바이러스들 중에서도 특히 커기가 작은 바이러스로서 피막(coat)을 둘러싸는 막(envelop) 이 없다. 폴리오바이러스는 (+) 가닥의 단일 RNA 게놈을 갖는데 이는 한 개의 해독판 (open reading frame)을 이용하여 다단백전구체를 만든 후 바이러스 자체의 단백질분해효소에 의해 스스로 잘라져서 궁극적으로느 특이한 기능을 갖는 여러개의 단백질이 된다. P1 다단백질전구체로부터 만들어지는 단백질들은 바이러스의 피막을 구성하는 성분이다. 단백질분해효소인 2A에 의한 최초의 절단은 구조단백질 P1 전구체와 구조단백질이 아닌 P2-P3간을 분리시켜준다. 단백질분해효소 2A는 진핵세포 판독개시인자(translation initiation factor) 4F의 한 subunit인 숙주단백질 p220의 절단에 간접으로 참여한다. 이 단백질의 절단은 캡(cap)에 의존하는 숙주세포의 대부분의 판독을 차단하게 되며 이는 판독에 사용되는 숙주세포의 모든 기구들을 캡에 의존하지 않는 폴리오바이러스 NA 특유의 판독을 위해 전적으로 사용할 수 있게 해준다. 2B, 2C, 2BC 단백질의 기능에 대해서는 많이 알려져 있지 않다. 2B, 2C, 2BC와 3CD 단백질들은 바이러스로 인해 만들어지는 소낭(vesicle)의 복제복합체에 함유되어 있으므로 바이러스의 RNA 복제시 중요한 역할을 함을 암시해준다. 새로이 만들어진 모든 바이러스 RNA는 VPg와 공유결합으로 연결되어 있다. VPg는 3AB로부터 만들어진 아미노산 22개 짜리의 폴리펩타이드이다. 3C와 3CD는 단백질분해소로 다단백질 전구체의 대부분의 절단부위를 잘라준다. 3C단백질은 숙주의 전사인자를 불활성화 시킴으로써 RNA polymer II와 III에 의한 전사를 저해한다. 3D는 RNA의존선RNA 중합효소이다. 폴리오바이러스는 (+)가닥 RNA 바이러스의 일반적인 복제양식을 따른다. 즉 (+) 가닥 RNA는 이와 상보적인 (-)가닥 RNA로 전사되고 이는 다시 (+)가닥 RNA의 합성을 위한 주형으로 사용된다. 폴리오바이러스의 RNA 합성은 세포내막에서 일어나는 데 RNA 복제에 요구되는 주형 RNA와 이때 필요한 단백질들이 어떤 방법으로 세포내막에서 모일 수 있는지는 아직 밝혀진 것이 적다. 바이러스입자의 형성은 세포막의 RNA 복제가 들어가는 데 피막단백질이 (+)가닥 RNA을 인식하는 표지 즉 packaging singal에 대해서는 거의 알려져 있지 않다. 폴리오바이러스 감염 후 첫 바이러스입자가 만들어지기 까는 약 6시간이 소요된다.

• Molecules and Cells
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• 제27권3호
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• pp.329-336
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• 2009

To evaluate the involvement of translation initiation factors eIF4E and eIFiso4E in Chilli veinal mottle virus (ChiVMV) infection in pepper, we conducted a genetic analysis using a segregating population derived from a cross between Capsicum annuum 'Dempsey' containing an elF4E mutation ($pvr1^2$) and C. annuum 'Perennial' containing an elFiso4E mutation (pvr6). C. annuum 'Dempsey' was susceptible and C. annuum 'Perennial' was resistant to ChiVMV. All $F_1$ plants showed resistance, and $F_2$ individuals segregated in a resistant-susceptible ratio of 166:21, indicating that many resistance loci were involved. Seventy-five $F_2$ and 329 $F_3$ plants of 17 families were genotyped with $pvr1^2$ and pvr6 allele-specific markers, and the genotype data were compared with observed resistance to viral infection. All plants containing homozygous genotypes of both $pvr1^2$ and pvr6 were resistant to ChiVMV, demonstrating that simultaneous mutations in elF4E and eIFiso4E confer resistance to ChiVMV in pepper. Genotype analysis of $F_2$ plants revealed that all plants containing homozygous genotypes of both $pvr1^2$ and pvr6 showed resistance to ChiVMV. In protein-protein interaction experiments, ChiVMV viral genome-linked protein (VPg) interacted with both eIF4E and eIFiso4E. Silencing of elF4E and eIFiso4E in the VIGS experiment showed reduction in ChiVMV accumulation. These results demonstrated that ChiVMV can use both eIF4E and eIFiso4E for replication, making simultaneous mutations in eIF4E and eIFiso4E necessary to prevent ChiVMV infection in pepper.