Proteomic Analysis of High-CO2-Inducible Extracellular Proteins in the Unicellular Green Alga, Chlamydomonas reinhardtii
Proteomic Analysis of High-CO2-Inducible Extracellular Proteins in the Unicellular Green Alga, Chlamydomonas reinhardtii
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DOI：
10.1093/pcp/pcr078
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发表时间：
2011-08-01
影响因子：
4.9
通讯作者：
Shiraiwa, Yoshihiro
中科院分区：
文献类型：
--
作者：
Baba, Masato;Suzuki, Iwane;Shiraiwa, Yoshihiro
单细胞绿色衣藻莱茵衣藻（Chlamydiumreinhardtii）通过CO2浓缩机制（CCM）的调节，能够适应大范围的CO2浓度。通过蛋白质组学分析，我们鉴定了在高CO_2条件下无细胞壁的C. reinhardtii，其将它们的细胞外基质释放到培养基中。当培养过程中CO2浓度从环境空气水平升高到3%时，藻类生长速率增加了1.5倍，胞外蛋白质的组成发生了明显变化，但胞内可溶性和不溶性蛋白质没有变化。蛋白质组学分析结果表明，129种细胞外蛋白中有22种在1 d和3 d时表达量增加，其中包括配子发生相关蛋白和富含羟脯氨酸的糖蛋白。然而，我们不能证明在高CO2条件下配子发生的诱导，这表明诱导信号可能是不完整的，不够强，或者只有高CO2条件可能不足以使细胞阶段进行性活跃配子的形成。然而，这些配子发生相关蛋白和/或富含羟脯氨酸的糖蛋白可能在高CO2条件下在细胞外具有新的作用。
The unicellular green alga Chlamydomonas reinhardtii can acclimate to a wide range of CO2 concentrations through the regulation of a CO2-concentrating mechanism (CCM). By proteomic analysis, here we identified the proteins which were specifically accumulated under high-CO2 conditions in a cell wall-less strain of C. reinhardtii which release their extracellular matrix into the medium. When the CO2 concentration was elevated from the ambient air level to 3% during culture, the algal growth rate increased 1.5-fold and the composition of extracellular proteins, but not intracellular soluble and insoluble proteins, clearly changed. Proteomic analysis data showed that the levels of 22 of 129 extracellular proteins increased for 1 and 3 d and such multiple high-CO2-inducible proteins include gametogenesis-related proteins and hydroxyproline-rich glycoproteins. However, we could not prove the induction of gametogenesis under high-CO2 conditions, suggesting that the inductive signal might be incomplete, not strong enough or that only high-CO2 conditions might be not sufficient for the cell stage to proceed to the formation of sexually active gametes. However, these gametogenesis-related proteins and/or hydroxyproline-rich glycoproteins may have novel roles outside the cell under high-CO2 conditions.