کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1935944 | 1050677 | 2008 | 6 صفحه PDF | دانلود رایگان |
Sulfur(S)-starvation was previously shown to induce the degradation of an acidic lipid in chloroplasts, sulfoquinovosyl diacylglycerol (SQDG), to yield a major internal S-source in a green alga, Chlamydomonas reinhardtii. We here found that the synthesis of phosphatidylglycerol (PG), the other acidic lipid in chloroplasts, is activated to elevate its content up to a level that just compensates for the loss of SQDG. Similar activation of PG synthesis was also observed in an SQDG-deficient mutant under S-replete conditions, which led us to propose that upregulation of PG synthesis under S-starved conditions occurs through direct sensing of SQDG-loss, but not of S-starvation. Moreover, thylakoid membranes isolated from S-starved cells were reduced in photosystem I activity on treatment with phospholipase A2 that specifically broke down PG, which suggested a critical role of PG that is increased under S-starved conditions in the maintenance of the photosystem I activity.
Journal: Biochemical and Biophysical Research Communications - Volume 369, Issue 2, 2 May 2008, Pages 660–665