气候变化领域集成服务门户(CCPortal): Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria

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DOI	10.1073/pnas.2012277118
	Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria
	Krauspe V.; Fahrner M.; Spät P.; Steglich C.; Frankenberg-Dinkel N.; Maček B.; Schilling O.; Hess W.R.
发表日期	2021
ISSN	00278424
卷号	118 期号:5
英文摘要	Phycobilisomes are the major pigment–protein antenna complexes that perform photosynthetic light harvesting in cyanobacteria, rhodophyte, and glaucophyte algae. Up to 50% of the cellular nitrogen can be stored in their giant structures. Accordingly, upon nitrogen depletion, phycobilisomes are rapidly degraded following an intricate genetic program. Here, we describe the role of NblD, a cysteine-rich, small protein in this process in cyanobacteria. Deletion of the nblD gene in the cyanobacterium Synechocystis sp. PCC 6803 prevented the degradation of phycobilisomes, leading to a nonbleaching (nbl) phenotype, which could be complemented by a plasmid-localized gene copy. Competitive growth experiments between the ΔnblD and the wild-type strain provided direct evidence for the physiological importance of NblD under nitrogen-limited conditions. Ectopic expression of NblD under nitrogen-replete conditions showed no effect, in contrast to the unrelated proteolysis adaptors NblA1 and NblA2, which can trigger phycobilisome degradation. Transcriptome analysis indicated increased nblA1/2 transcript levels in the ΔnblD strain during nitrogen starvation, implying that NblD does not act as a transcriptional (co) regulator. However, immunoprecipitation and far-western experiments identified the chromophorylated (holo form) of the phycocyanin β-subunit (CpcB) as its target, while apo-CpcB was not bound. The addition of recombinant NblD to isolated phycobilisomes caused a reduction in phycocyanin absorbance and a broadening and shifting of the peak to lower wavelengths, indicating the occurrence of structural changes. These data demonstrate that NblD plays a crucial role in the coordinated dismantling of phycobilisomes and add it as a factor to the genetically programmed response to nitrogen starvation. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Cyanobacteria; Gene expression; Nitrogen starvation; Photosynthesis; Phycobilisomes
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180815
作者单位	Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany; Institute for Surgical Pathology, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, 79106, Germany; Faculty of Biology, Albert-Ludwigs University of Freiburg, Freiburg, 79104, Germany; Spemann Graduate School of Biology and Medicine, Albert-Ludwigs University of Freiburg, Freiburg, 79104, Germany; Department of Quantitative Proteomics, Interfaculty Institute for Cell Biology, University of Tübingen, Tübingen, 72076, Germany; Department of Microbiology, Faculty of Biology, University of Kaiserslautern, Kaiserslautern, 67663, Germany
推荐引用方式 GB/T 7714	Krauspe V.,Fahrner M.,Spät P.,et al. Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria[J],2021,118(5).
APA	Krauspe V..,Fahrner M..,Spät P..,Steglich C..,Frankenberg-Dinkel N..,...&Hess W.R..(2021).Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria.Proceedings of the National Academy of Sciences of the United States of America,118(5).
MLA	Krauspe V.,et al."Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria".Proceedings of the National Academy of Sciences of the United States of America 118.5(2021).