Fig 5. Impact of WT or mutant 98K proteins on processing of precursor protein 206K.

Arabidopsis protoplasts were transfected with the expression vectors indicated, alone or in combination. Cells were collected 48 hpt and total protein extracts were subjected to 8% SDS-PAGE and immunoblot analysis with anti-66K (top) or anti-98K (bottom). The positions of molecular mass markers are indicated on the left, and that of viral proteins on the right. Protein 206K corresponds to the substrate protein, 66K and 98K to its mature cleavage products. In the lower panel, the mature 98K product resulting from cleavage of 206K is obscured by the 98K produced in trans from pΩ-98K. The shorter 85K protein corresponds to a nonspecific degradation product of 98K occurring during sample extraction and protein analysis [31]. Each mutant was analyzed in two independent experiments.