The translation of the genotype into phenotype, represented for example by the expression of genes encod- ing enzymes required for the biosynthesis of phytochemicals that are important for interaction of plants with t...The translation of the genotype into phenotype, represented for example by the expression of genes encod- ing enzymes required for the biosynthesis of phytochemicals that are important for interaction of plants with the environment, is largely carried out by transcription factors （TFs） that recognize specific cis-regulatory elements in the genes that they control. TFs and their target genes are organized in gene regulatory net- works （GRNs）, and thus uncovering GRN architecture presents an important biological challenge necessary to explain gene regulation. Linking TFs to the genes they control, central to understanding GRNs, can be car- ried out using gene- or TF-centered approaches. In this study, we employed a gene-centered approach uti- lizing the yeast one-hybrid assay to generate a network of protein-DNA interactions that participate in the transcriptional control of genes involved in the biosynthesis of maize phenolic compounds including gen- eral phenylpropanoids, lignins, and flavonoids. We identified 1100 protein-DNA interactions involving 54 phenolic gene promoters and 568 TFs. A set of 11 TFs recognized 10 or more promoters, suggesting a role in coordinating pathway gene expression. The integration of the gene-centered network with informa- tion derived from TF-centered approaches provides a foundation for a phenolics GRN characterized by in- terlaced feed-forward loops that link developmental regulators with biosynthetic genes.展开更多
Chloroplasts and mitochondria contain a family of putative preprotein and amino acid transporters designated PRAT. Here, we analyzed the role of two previously characterized PRAT protein family members, encoded by At3...Chloroplasts and mitochondria contain a family of putative preprotein and amino acid transporters designated PRAT. Here, we analyzed the role of two previously characterized PRAT protein family members, encoded by At3g49560 （HP30） and At5g24650 （HP30-2）, in planta using a combination of genetic, cell biological and biochemical approaches. Expression studies and green fluorescent protein tagging identified HP30-2 both in chloroplasts and mitochondria, whereas HP30 was located exclusively in chloroplasts. Biochemical evidence was obtained for an association of mitochondrial HP30-2 with two distinct protein complexes, one containing the inner membrane translocase TIM22 and the other containing an alternative NAD（P）H dehydrogenase subunit （NDCI） implicated in a respiratory complex 1-1ike electron trans- port chain. Through its association with TIM22, HP30-2 is involved in the uptake of carrier proteins and other, hydrophobic membrane proteins lacking cleavable N H2-terminal presequences, whereas HP30-2＇s interaction with NDC1 may permit controlling mitochondrial biogenesis and activity.展开更多
文摘The translation of the genotype into phenotype, represented for example by the expression of genes encod- ing enzymes required for the biosynthesis of phytochemicals that are important for interaction of plants with the environment, is largely carried out by transcription factors （TFs） that recognize specific cis-regulatory elements in the genes that they control. TFs and their target genes are organized in gene regulatory net- works （GRNs）, and thus uncovering GRN architecture presents an important biological challenge necessary to explain gene regulation. Linking TFs to the genes they control, central to understanding GRNs, can be car- ried out using gene- or TF-centered approaches. In this study, we employed a gene-centered approach uti- lizing the yeast one-hybrid assay to generate a network of protein-DNA interactions that participate in the transcriptional control of genes involved in the biosynthesis of maize phenolic compounds including gen- eral phenylpropanoids, lignins, and flavonoids. We identified 1100 protein-DNA interactions involving 54 phenolic gene promoters and 568 TFs. A set of 11 TFs recognized 10 or more promoters, suggesting a role in coordinating pathway gene expression. The integration of the gene-centered network with informa- tion derived from TF-centered approaches provides a foundation for a phenolics GRN characterized by in- terlaced feed-forward loops that link developmental regulators with biosynthetic genes.
基金supported by the Chaire d’Excellence Program of the French Ministry of National Education and Research(to CR)
文摘Chloroplasts and mitochondria contain a family of putative preprotein and amino acid transporters designated PRAT. Here, we analyzed the role of two previously characterized PRAT protein family members, encoded by At3g49560 （HP30） and At5g24650 （HP30-2）, in planta using a combination of genetic, cell biological and biochemical approaches. Expression studies and green fluorescent protein tagging identified HP30-2 both in chloroplasts and mitochondria, whereas HP30 was located exclusively in chloroplasts. Biochemical evidence was obtained for an association of mitochondrial HP30-2 with two distinct protein complexes, one containing the inner membrane translocase TIM22 and the other containing an alternative NAD（P）H dehydrogenase subunit （NDCI） implicated in a respiratory complex 1-1ike electron trans- port chain. Through its association with TIM22, HP30-2 is involved in the uptake of carrier proteins and other, hydrophobic membrane proteins lacking cleavable N H2-terminal presequences, whereas HP30-2＇s interaction with NDC1 may permit controlling mitochondrial biogenesis and activity.
