A map for the interactions of the major proteins from Potato virus A (PVA) and Pea seed-borne mosaic virus (PSbMV) (members of the genus Potyvirus, family Potyviridae) was generated using the yeast two-hybrid system (YTHS). Interactions were readily detected with five PVA protein combinations (HC–HC, HC–CI, VPg–VPg, NIa–NIb and CP–CP) and weak but reproducible interactions were detected for seven additional combinations (P1–CI, P3–NIb, NIaPro–NIb, VPg–NIa, VPg–NIaPro, NIaPro–NIa and NIa–NIa). In PSbMV, readily detectable interactions were found in five protein combinations (HC–HC, VPg–VPg, VPg–NIa, NIa–NIa and NIa–NIb) and weaker but reproducible interactions were detected for three additional combinations (P3–NIa, NIa–NIaPro and CP–CP). The self-interactions of HC, VPg, NIa and CP and the interactions of VPg–NIa, NIa–NIaPro and NIa–NIb were, therefore, common for the two potyviruses. The multiple protein interactions revealed in this study shed light on the co-ordinated functions of potyviral proteins involved in virus movement and replication.
Cloning of hnRNP E1 cDNA via yeast two-hybrid system and a study on protein-protein interaction between hnRNP E1 and hnRNP K