Pyrenoid proteomics reveals independent evolution of the CO2-concentrating organelle in chlorarachniophytes

• 成果类型: Article
• 署名作者: Moromizato, Rena; Fukuda, Kodai; Suzuki, Shigekatsu; Motomura, Taizo; Nagasato, Chikako; Hirakawa, Yoshihisa
• 署名单位: University of Tsukuba; University of Tsukuba; National Institute for Environmental Studies - Japan; Hokkaido University; University of Tsukuba
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13067
• DOI: 10.1073/pnas.2318542121
• 发表日期: 2024-03-05
• 关键词: carbon-concentrating mechanism; secondary plastids; genome sequences; protein; rubisco; chloroplast; photosynthesis; amoebiformis; ORGANIZATION; origin

摘要

Pyrenoids are microcompartments that are universally found in the photosynthetic plastids of various eukaryotic algae. They contain ribulose-1,5- bisphosphate carboxylase/oxygenase (Rubisco) and play a pivotal role in facilitating CO2 assimilation via CO2- concentrating mechanisms (CCMs). Recent investigations involving model algae have revealed that pyrenoid- associated proteins participate in pyrenoid biogenesis and CCMs. However, these organisms represent only a small part of algal lineages, which limits our comprehensive understanding of the diversity and evolution of pyrenoid-based CCMs. Here we report a pyrenoid proteome of the chlorarachniophyte algaAmorphochlora amoebiformis, which possesses complex plastids acquired through secondary endosymbiosis with green algae. Proteomic analysis using mass spectrometry resulted in the identification of 154 potential pyrenoid components. Subsequent localization experiments demonstrated the specific targeting of eight proteins to pyrenoids. These included a putative Rubisco- binding linker, carbonic anhydrase, membrane transporter, and uncharacterized GTPase proteins. Notably, most of these proteins were unique to this algal lineage. We suggest a plausible scenario in which pyrenoids in chlorarachniophytes have evolved independently, as their components are not inherited from green algal pyrenoids.