Systems biology approach in Chlamydomonas reveals connections between copper nutrition and multiple metabolic steps.
Plant Cell
; 23(4): 1273-92, 2011 Apr.
Article
em En
| MEDLINE
| ID: mdl-21498682
ABSTRACT
In this work, we query the Chlamydomonas reinhardtii copper regulon at a whole-genome level. Our RNA-Seq data simulation and analysis pipeline validated a 2-fold cutoff and 10 RPKM (reads per kilobase of mappable length per million mapped reads) (~1 mRNA per cell) to reveal 63 CRR1 targets plus another 86 copper-responsive genes. Proteomic and immunoblot analyses captured 25% of the corresponding proteins, whose abundance was also dependent on copper nutrition, validating transcriptional regulation as a major control mechanism for copper signaling in Chlamydomonas. The impact of copper deficiency on the expression of several O2-dependent enzymes included steps in lipid modification pathways. Quantitative lipid profiles indicated increased polyunsaturation of fatty acids on thylakoid membrane digalactosyldiglycerides, indicating a global impact of copper deficiency on the photosynthetic apparatus. Discovery of a putative plastid copper chaperone and a membrane protease in the thylakoid suggest a mechanism for blocking copper utilization in the chloroplast. We also found an example of copper sparing in the N assimilation pathway the replacement of copper amine oxidase by a flavin-dependent backup enzyme. Forty percent of the targets are previously uncharacterized proteins, indicating considerable potential for new discovery in the biology of copper.
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Coleções:
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Base de dados:
MEDLINE
Assunto principal:
Chlamydomonas
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Cobre
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Biologia de Sistemas
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Metabolismo
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Fenômenos Fisiológicos da Nutrição
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article