A green dichromophoric protein enabling foliage mimicry in arthropods

• 成果类型: Article
• 署名作者: Egorkin, Nikita A.; Aleksin, Anatoly M.; Sedlov, Ilya A.; Zhiganov, Nikita I.; Bodunova, Daria V.; Varfolomeeva, Larisa A.; Slonimskiy, Yury B.; Ziganshin, Rustam H.; Popov, Vladimir O.; Boyko, Konstantin M.; Vassilevski, Alexander A.; Maksimov, Eugene G.; Sluchanko, Nikolai N.
• 署名单位: Research Center of Biotechnology RAS; Russian Academy of Sciences; Lomonosov Moscow State University; Lomonosov Moscow State University; Lomonosov Moscow State University; Lomonosov Moscow State University; Research Center of Biotechnology RAS; Russian Academy of Sciences; Russian Academy of Sciences; Pushchino Scientific Center for Biological Research (PSCBI) of the Russian Academy of Sciences; Institute of Bioorganic Chemistry of the Russian Academy of Sciences; Russian Academy of Sciences; Pushchino Scientific Center for Biological Research (PSCBI) of the Russian Academy of Sciences; Institute of Bioorganic Chemistry of the Russian Academy of Sciences
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13814
• DOI: 10.1073/pnas.2502567122
• 发表日期: 2025-06-10
• 关键词: biliverdins ix-alpha; molecular-structure; insect; vitellogenin; purification; hemolymph; vitellin; bilin; heme

摘要

Molecular mechanisms underlying the green insect camouflage have puzzled researchers for over a century. Here, we isolated and identified a green water-soluble protein from the integument of bush-cricket Tettigonia cantans. De novo sequencing and cloning revealed a severely fragmented form of vitellogenins, ubiquitous and multifunctional, but still largely enigmatic glycolipoproteins essential for embryonic development and lacking structural characterization. The distinctive color of the identified chromoprotein results from binding of a remarkable combination of farnesylated bilins (recently identified, tentative heme A catabolites) and xanthophylls, which commensurably absorb light in the 600 to 700 nm and 400 to 550 nm spectral regions and thereby produce a hue that perfectl y mimics foliage. The high-resolution crystal structure of this unique similar to 80 kDa dichromophoric protein, which we named dibilinoxanthinin (DBXN), revealed two DBXN protomers, each consisting of three polypeptides, with a novel fold enclosing a large hydrophobic cavity that accommodates two bilins, two luteins, and four phosphatidylcholines, all anchored by hydrogen bonds and giving DBXN unique biochemical and optical properties. Among the green insects tested, some contained yellow and blue chromophores in separate fractions, while others had green proteins similar to DBXN, although not necessarily of the same size. Surprisingly, we isolated and identified a larger vitellogenin proteoform with DBXN-like absorption, from the green huntsman spider Micrommata virescens. These data illustrate striking variations in the DBXN-related pigmentation mechanism among different green arthropods and suggest that vitellogenins may have undergone neofunctionalization, reflecting their potential for functional diversification.