Fig. 2. The C-terminal region of Mon2p is essential for cell growth under membrane stress. (A) Schematic representation of the Mon2p-GFP fusion with its six conserved domains (A-F) and various truncated Mon2p-GFP derivatives: Mon2[A-F]p/(pFP45), Mon2[A-E]p/(pOD123), Mon2[A-d]p/(pFP46), Mon2[A-C]p/(pOD124), Mon2[A-B]p/(pOD125), Mon2[A]p/(pFP46), Mon2[B-F]p/(pOD126), Mon2[d-F]p/(pOD122) and Mon2[E-F]p/(pOD127). The D domain is denoted with a lowercase d when it is not entirely expressed. Growth complementation of the different Mon2p-GFP derivatives were tested in YFP44 (mon2/chc1-521) cells at 30°C and indicated as followed: +++, growth identical to wild-type cells; ++ and +, growth is slightly and strongly reduced, respectively; –, no growth. (B) Western blotting. Whole cell extracts of YFP93 (mon2) cells transformed with constructs encoding GFP-tagged truncations (lanes labelled 1-9 correspond to constructs in A) were resolved by SDS-PAGE. The expressed protein fragments were detected by GFP antibody. A released GFP fragment is labeled with 1 and the presence of a doublet with 2. (C) YFP93 (mon2) cells expressing the Mon2p-GFP derivatives containing the indicated domains were grown on SD-LEU plates containing 0 or 20 µM CPZ for 36 hours at 25°C.