GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:21515910

From GONUTS
Jump to: navigation, search
Citation

Qiao, J, Ma, C, Wimmelbacher, M, Börnke, F and Luo, M (2011) Two novel proteins, MRL7 and its paralog MRL7-L, have essential but functionally distinct roles in chloroplast development and are involved in plastid gene expression regulation in Arabidopsis. Plant Cell Physiol. 52:1017-30

Abstract

Chloroplast development requires the coordinated action of various proteins, many of which remain to be identified. Here, we report two novel genes, Mesophyll-cell RNAi Library line 7 (MRL7) and MRL7-Like (MRL7-L), that are involved in this process. An Arabidopsis knock-down transgenic plant (MRL7-RNAi) with delayed-greening phenotype was isolated from an RNA interference (RNAi) transformant library. Cotyledons and young leaves of MRL7-RNAi were pale in seedlings and gradually greened as the plant matured, while a knock-out in the MRL7 gene was seedling lethal. The MRL7 protein was shown to co-localize with a marker protein for nucleoids in chloroplasts, indicative of a role for the protein in chloroplast nucleic acid metabolism. Accordingly, chloroplast development was arrested upon loss of MRL7 function and the expression of plastid-encoded genes transcribed by plastid-encoded RNA polymerase (PEP) was significantly reduced in MRL7 knock-down and knock-out plants. A paralog of MRL7 (MRL7-L) was identified in the Arabidopsis genome. Both MRL7 and MRL7-L are only found in land plants and encode previously uncharacterized proteins without any known conserved domain. Like MRL7, knock-down of MRL7-L also resulted in a virescent phenotype, and a similar effect on plastid gene expression. However, the MRL7-L protein was localized to the chloroplast stroma. Taken together, our data indicate that the two paralogous proteins MRL7 and MRL7-L have essential but distinct roles during early chloroplast development and are involved in regulation of plastid gene expression.

Links

PubMed Online version:10.1093/pcp/pcr054

Keywords

Arabidopsis/genetics; Arabidopsis/growth & development; Arabidopsis/metabolism; Arabidopsis/ultrastructure; Arabidopsis Proteins/genetics; Arabidopsis Proteins/metabolism; Chloroplasts/genetics; Chloroplasts/metabolism; Chloroplasts/physiology; Chloroplasts/ultrastructure; Cotyledon/growth & development; Cotyledon/metabolism; DNA-Directed RNA Polymerases/genetics; DNA-Directed RNA Polymerases/metabolism; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Gene Knockout Techniques; Genes, Lethal; Genotype; Microscopy, Fluorescence; Phenotype; Phylogeny; Plant Leaves/growth & development; Plant Leaves/metabolism; Plants, Genetically Modified/genetics; Plants, Genetically Modified/growth & development; Plants, Genetically Modified/metabolism; Plants, Genetically Modified/ultrastructure; RNA Interference; Sequence Homology, Amino Acid; Transcription, Genetic

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

ARATH:MRL7

involved_in

GO:0006355: regulation of transcription, DNA-templated

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

ARATH:MRL7

located_in

GO:0042644: chloroplast nucleoid

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

ARATH:MRL7

involved_in

GO:0009658: chloroplast organization

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

ARATH:MRL7L

involved_in

GO:0006355: regulation of transcription, DNA-templated

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

ARATH:MRL7L

located_in

GO:0009570: chloroplast stroma

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

ARATH:MRL7L

involved_in

GO:0009658: chloroplast organization

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.