Chloroplast Sec14-like 1 (CPSFL1) is essential for normal chloroplast development and affects carotenoid accumulation in <i>Chlamydomonas</i>
José G. García‐Cerdán, Eva M. Schmid, Tomomi Takeuchi, Ian McRae, Kent McDonald, Nichakarn Yordduangjun, Ahmed M. Hassan, Patricia Grob, C. Shan Xu, Harald F. Hess, Daniel A. Fletcher, Eva Nogales, Krishna Niyogi
Abstract
Significance Carotenoids are essential molecules in oxygenic photoautotrophs, and they fulfill essential requirements for human and animal nutrition. How carotenoid accumulation is regulated in the chloroplast, a cyanobacterium-derived organelle, remains poorly understood, despite significant advancements in identifying enzymes of the carotenoid biosynthetic pathway. This study identifies a role of chloroplast Sec14-like 1 (CPSFL1), a CRAL-TRIO protein of eukaryotic origin, in modulation of carotenoid biosynthesis and accumulation in the chloroplast. The CPSFL1 protein represents an isoprenoid- and carotenoid-binding protein that associates with membranes through interactions with the phospholipid phosphatidic acid. These findings have implications for understanding carotenoid biosynthesis and optimizing algal carotenoid nutritional quality.