Reciprocal Regulation of Protein Synthesis and Carbon Metabolism for Thylakoid Membrane Biogenesis
(A) Cell subfractionation. Cell fractions were prepared as described in Materials and Methods. We separated 30 µg of each protein fraction by SDS-PAGE and subjected them to immunoblot analysis. The blot was probed with antibodies against DLA2 (α-DLA2), the large subunit of Rubisco (α-RbcL), and the mitochondrial AOX (α-AOX, Agrisera). cp, chloroplasts; cTs, crude thylakoids; mt, mitochondria; s, stroma; wc, whole cells. (B) Analysis of the accumulation of DLA2–GFP fusion proteins in the transformed algal UVM4 strain by laser-scanning microscopy. Chlorophyll autofluorescence (Chlorophyll) and expression of GFP without (GFP) or with an N-terminal fusion of the first 114 aa of DLA2 (TP–DLA2–GFP). The untransformed UVM recipient strain served as control (WT). A merged image of the chlorophyll autofluorescence and GFP signals is shown (Overlay).