The GroEL protein of the whitefly Bemisia tabaci interacts with the coat protein of transmissible and nontransmissible begomoviruses in the yeast two-hybrid system.
We have previously suggested that a GroEL homolog produced by the whitefly Bemisia tabaci endosymbiotic bacteria interacts in the insect hemolymph with particles of Tomato yellow leaf curl virus from Israel (TYLCV-Is), ensuring the safe circulative transmission of the virus. We have now addressed the question of whether the nontransmissibility of Abutilon mosaic virus from Israel (AbMV-Is) is related to a lack of association between GroEL and the virus coat protein (CP). Translocation analysis has shown that, whereas TYLCV-Is DNA is conspicuous in the digestive tract, hemolymph, and salivary glands of B. tabaci 8 h after acquisition feeding started, AbMV-Is DNA was detected only in the insect digestive tract, even after 96 h. To determine whether AbMV-Is particles were rapidly degraded in the hemolymph as a result of their inability to interact with GroEL, we have isolated a GroEL gene from B. tabaci and used a yeast two-hybrid assay to compare binding of the CP of TYLCV-Is and AbMV-Is to the insect GroEL. The yeast assay showed that the CPs of the two viruses are able to bind efficiently to GroEL. We therefore suggest that, although GroEL-CP interaction in the hemolymph is a necessary condition for circulative transmission, the nontransmissibility of AbMV-Is is not the result of lack of binding to GroEL in the B. tabaci hemolymph, but most likely results from an inability to cross the gut/hemolymph barrier.
Morin
S
S
Department of Field Crops and Genetics, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Ghanim
M
M
Sobol
I
I
Czosnek
H
H
D000595:Amino Acid Sequence; D000818:Animals; D002213:Capsid / Q000378:metabolism*; D018834:Chaperonin 60 / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004064:Digestive System / Q000821:virology; D017791:Geminiviridae / Q000235:genetics / Q000378:metabolism*; D003368:Gossypium; D006430:Hemiptera / Q000378:metabolism* / Q000821:virology; D006458:Hemolymph / Q000821:virology; D007557:Israel; D008969:Molecular Sequence Data; D009029:Mosaic Viruses / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D012469:Salivary Glands / Q000821:virology; D020798:Two-Hybrid System Techniques
D018834:Chaperonin 60