State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
University of Chinese Academy of Sciences, Beijing, China.
Microbiol Spectr. 2021 Oct 31;9(2):e0049021. doi: 10.1128/Spectrum.00490-21. Epub 2021 Sep 15.
Cyanobacteria, capable of oxygenic photosynthesis, play a vital role in nitrogen and carbon cycles. sp. PCC 7120 ( 7120) is a model cyanobacterium commonly used to study cell differentiation and nitrogen metabolism. Although its genome was released in 2002, a high-quality genome annotation remains unavailable for this model cyanobacterium. Therefore, in this study, we performed an in-depth proteogenomic analysis based on high-resolution mass spectrometry (MS) data to refine the genome annotation of 7120. We unambiguously identified 5,519 predicted protein-coding genes and revealed 26 novel genes, 75 revised genes, and 27 different kinds of posttranslational modifications in 7120. A subset of these novel proteins were further validated at both the mRNA and peptide levels. Functional analysis suggested that many newly annotated proteins may participate in nitrogen or cadmium/mercury metabolism in 7120. Moreover, we constructed an updated 7120 database based on our proteogenomic results and presented examples of how the updated database could be used to improve the annotation of proteomic data. Our study provides the most comprehensive annotation of the 7120 genome thus far and will serve as a valuable resource for the study of nitrogen metabolism in 7120. Cyanobacteria are a large group of prokaryotes capable of oxygenic photosynthesis and play a vital role in nitrogen and carbon cycles on Earth. 7120 is a commonly used model cyanobacterium for studying cell differentiation and nitrogen metabolism. In this study, we presented the first comprehensive draft map of the 7120 proteome and a wide range of posttranslational modifications. In addition, we constructed an updated database of 7120 based on our proteogenomic results and presented examples of how the updated database could be used for system-level studies of 7120. Our study provides the most comprehensive annotation of 7120 genome and a valuable resource for the study of nitrogen metabolism in this model cyanobacterium.
蓝藻能够进行产氧光合作用，在氮循环和碳循环中起着至关重要的作用。 sp. PCC 7120（7120）是一种常用的模式蓝藻，用于研究细胞分化和氮代谢。尽管其基因组于 2002 年发布，但该模式蓝藻的高质量基因组注释仍然不可用。因此，在这项研究中，我们基于高分辨率质谱（MS）数据进行了深入的蛋白质基因组分析，以完善 7120 的基因组注释。我们明确鉴定了 5519 个预测的蛋白编码基因，并在 7120 中揭示了 26 个新基因、75 个修订基因和 27 种不同的翻译后修饰。这些新蛋白质的一部分进一步在 mRNA 和肽水平上得到验证。功能分析表明，许多新注释的蛋白质可能参与 7120 中的氮或镉/汞代谢。此外，我们基于蛋白质基因组学结果构建了一个更新的 7120 数据库，并展示了如何使用更新的数据库来改进蛋白质组数据注释的示例。我们的研究提供了迄今为止对 7120 基因组最全面的注释，将成为研究 7120 中氮代谢的宝贵资源。 蓝藻是一大类能够进行产氧光合作用的原核生物，在地球的氮循环和碳循环中起着至关重要的作用。 7120 是一种常用的模式蓝藻，用于研究细胞分化和氮代谢。在这项研究中，我们展示了 7120 蛋白质组的第一张综合草图和广泛的翻译后修饰。此外，我们基于蛋白质基因组学结果构建了一个更新的 7120 数据库，并展示了如何使用更新的数据库进行 7120 的系统水平研究。我们的研究提供了对 7120 基因组最全面的注释，为该模式蓝藻中氮代谢的研究提供了有价值的资源。
