Immobility of phycobilins in the thylakoid lumen of a cryptophyte suggests that protein diffusion in the lumen is very restricted.
The thylakoid lumen is an important photosynthetic compartment which is the site of key steps in photosynthetic electron transport. The fluidity of the lumen could be a major constraint on photosynthetic electron transport rates. We used Fluorescence Recovery After Photobleaching in cells of the cryptophyte alga Rhodomonas salina to probe the diffusion of phycoerythrin in the lumen and chlorophyll complexes in the thylakoid membrane. In neither case was there any detectable diffusion over a timescale of several minutes. This indicates very restricted phycoerythrin mobility. This may be a general feature of protein diffusion in the thylakoid lumen.
Kana
Radek
R
Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81 Trebon, Czech Republic.
Prásil
Ondrej
O
Mullineaux
Conrad W
CW
D044785:Cryptophyta / Q000378:metabolism*; D004058:Diffusion; D036681:Fluorescence Recovery After Photobleaching; D008954:Models, Biological; D052980:Phycobilins / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D020524:Thylakoids / Q000378:metabolism*; D013997:Time Factors
D052980:Phycobilins; D011506:Proteins