Figure 6.

In vivo labeling of plastid-encoded stromal proteins. A, Pulse-chase labeling of the chloroplast stromal proteins. After 20-min pulse labeling (indicated as 0) and chase for 0.5, 1, and 2 h, total soluble proteins were separated by SDS-urea-PAGE and the labeled proteins were visualized by autoradiography. B and C, Pulse-chase labeling of stromal protein complexes. After pulse (indicated as 0) and chase for 30 and 60 min, stromal protein complexes were isolated and separated by CN-PAGE (B) and subsequent 2D/SDS-urea-PAGE (C). The labeled proteins were visualized by autoradiography. CF₁ Sub., CF₁ subcomplex of chloroplast ATP synthase. The band at the top of the CN-gel (indicated by an asterisk) (B) may represent protein aggregates or the chaperonin complex containing unfolded protein.