Regulation of photosystem I-light-harvesting complex I from a red alga Cyanidioschyzon merolae in response to light inte
- PDF / 4,475,290 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 85 Downloads / 170 Views
ORIGINAL ARTICLE
Regulation of photosystem I‑light‑harvesting complex I from a red alga Cyanidioschyzon merolae in response to light intensities Lijing Chang1,2 · Lirong Tian1,3 · Fei Ma1 · Zhiyuan Mao1,2 · Xiaochi Liu1,2 · Guangye Han1 · Wenda Wang1 · Yanyan Yang1 · Tingyun Kuang1 · Jie Pan1,5 · Jian‑Ren Shen1,4 Received: 9 April 2020 / Accepted: 21 July 2020 © Springer Nature B.V. 2020
Abstract Photosynthetic organisms use different means to regulate their photosynthetic activity in respond to different light conditions under which they grow. In this study, we analyzed changes in the photosystem I (PSI) light-harvesting complex I (LHCI) supercomplex from a red alga Cyanidioschyzon merolae, upon growing under three different light intensities, low light (LL), medium light (ML), and high light (HL). The results showed that the red algal PSI-LHCI is separated into two bands on blue-native PAGE, which are designated PSI-LHCI-A and PSI-LHCI-B, respectively, from cells grown under LL and ML. The former has a higher molecular weight and binds more Lhcr subunits than the latter. They are considered to correspond to the two types of PSI-LHCI identified by cryo-electron microscopic analysis recently, namely, the former with five Lhcrs and the latter with three Lhcrs. The amount of PSI-LHCI-A is higher in the LL-grown cells than that in the ML-grown cells. In the HL-grown cells, PSI-LHCI-A completely disappeared and only PSI-LHCI-B was observed. Furthermore, PSI core complexes without Lhcr attached also appeared in the HL cells. Fluorescence decay kinetics measurement showed that Lhcrs are functionally connected with the PSI core in both PSI-LHCI-A and PSI-LHCI-B obtained from LL and ML cells; however, Lhcrs in the PSI-LHCI-B fraction from the HL cells are not coupled with the PSI core. These results indicate that the red algal PSI not only regulates its antenna size but also adjusts the functional connection of Lhcrs with the PSI core in response to different light intensities. Keywords Light adaptation · PSI-LHCI · Light-harvesting antenna · Fluorescence decay · Red algae · Cyanidioschyzon merolae
Introduction Lijing Chang and Lirong Tian have contributed equally to this work. * Jian‑Ren Shen [email protected]‑u.ac.jp 1
Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No, 20, Nanxincun, Xiangshan, Beijing 100093, China
2
University of Chinese Academy of Sciences, Yuquan Road, Shijingshan District, Beijing 100049, China
3
Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
4
Research Institute for Interdisciplinary Science, Okayama University, Okayama 700‑8530, Japan
5
Present Address: Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
Adaptation to various light environments is one of the most important capabilities that photosynthetic organisms possess in order to achieve highest efficiency of light energy utilization in ev
Data Loading...
