Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcription profiling of Arabidopsis polysomal and non-polysomal RNA samples isolated from 10-day-old wild-type and eif3h mutant plants

ABSTRACT: Microarray comparisons of polysome loading in wild-type Arabidopsis and eif3h mutant; Goal: ; To find the target mRNAs that are translationally regulated by eIF3h. BACKGROUND: The eukaryotic translation initiation factor eIF3 has multiple roles during the initiation of translation of cytoplasmic mRNAs. However, the contributions of individual subunits of eIF3 to the translation of specific mRNAs remain poorly understood. RESULTS: Working with stable reporter transgenes in Arabidopsis thaliana it was demonstrated that the h subunit of; eIF3 contributes to the efficient translation initiation of mRNAs harboring upstream open reading frames (uORFs) in their 5â leader sequence. uORFs, which can function as devices for translational regulation, are present in over 30% of Arabidopsis mRNAs, and are enriched among mRNAs for transcriptional regulators and protein modifying enzymes. Microarray comparisons of polysome loading in wild-type and eif3h mutant plants revealed that eIF3h generally helps to maintain efficient polysome loading of mRNAs harboring multiple uORFs. Independently, eIF3h also boosted polysome loading of mRNAs with long coding sequences. Moreover, the lesion in eIF3h revealed a concerted upregulation of translation for specific functional subgroups of mRNAs, including ribosomal proteins and proteins involved in photosynthesis. CONCLUSIONS: The intact eIF3h protein contributes to efficient translation initiation on 5â leader sequences harboring multiple uORFs, although mRNA features independent of uORFs were also implicated. Moreover, our data suggest that regulons of translational control can be revealed by mutations in generic translation initiation factors. Experiment Overall Design: Polysomal and non-polysomal RNA samples were isolated from 10-day-old wild-type and eif3h mutant plants. The translation state (ratio between the polysome and non-polysome, PL/NP) for each gene in the WT and in the mutant was separately established, and then the translation states between the genotype were compared.

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Albrecht von Arnim

PROVIDER: E-GEOD-6024 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Publications

On the functions of the h subunit of eukaryotic initiation factor 3 in late stages of translation initiation.

Kim Byung-Hoon BH Cai Xue X Vaughn Justin N JN von Arnim Albrecht G AG

Genome biology 20070101 4

<h4>Background</h4>The eukaryotic translation initiation factor 3 (eIF3) has multiple roles during the initiation of translation of cytoplasmic mRNAs. How individual subunits of eIF3 contribute to the translation of specific mRNAs remains poorly understood, however. This is true in particular for those subunits that are not conserved in budding yeast, such as eIF3h.<h4>Results</h4>Working with stable reporter transgenes in Arabidopsis thaliana mutants, it was demonstrated that the h subunit of e ...[more]

PMID: 17439654

Similar Datasets

Project description:In eukaryotes, regulation of mRNA translation enables a fast, localized and finely tuned expression of gene products. Within the translation process, the first stage of translation initiation is most rigorously modulated by the actions of eukaryotic initiation factors (eIFs) and their associated proteins. These 11 eIFs catalyze the joining of the tRNA, mRNA and rRNA into a functional translation complex. Their activity is influenced by a wide variety of extra- and intracellular signals, ranging from global, such as hormone signaling and unfolded proteins, to specific, such as single amino acid imbalance and iron deficiency. Their action is correspondingly comprehensive, in increasing or decreasing recruitment and translation of most cellular mRNAs, and specialized, in targeting translation of mRNAs with regulatory features such as a 5’ terminal oligopyrimidine tract (TOP), upstream open reading frames (uORFs), or an internal ribosomal entry site (IRES). In mammals, two major pathways are linked to targeted mRNA translation. The target of rapamycin (TOR) kinase induces translation of TOP and perhaps other subsets of mRNAs, whereas a family of eIF2 kinases does so with mRNAs containing uORFs or an IRES. TOR targets translation of mRNAs that code for proteins involved in translation, an action compatible with its widely accepted role in regulating cellular growth. The four members of the eIF2 kinase family increase translation of mRNAs coding for stress response proteins such as transcription factors and chaperones. Though all four kinases act on one main substrate, eIF2, published literature demonstrates both common and unique effects by each kinase in response to its specific activating stress. This suggests that the activated eIF2 kinases regulate the translation of both a global and a specific set of mRNAs. Up to now, few studies have attempted to test such a hypothesis; none has been done in mammals. We use array analysis to determine the global mRNA shift into polysomes following a stress response, and to compare the translational response following activation of GCN2 versus PERK, two of the four eIF2alpha kinases. Experiment Overall Design: Gcn2 wild-type or knockout mouse liver were perfused with complete amino acids media or media lacking methionine for RNA extraction and hybridization of Affymetrix microarrays. RNA was extracted from unfractionated liver samples and polysome fraction of samples separated on sucrose density gradient. To minimize biological variations, we pooled RNA from two perfused liver samples to use in each array analysis. The conditions were total and polysome fraction of Gcn2+/+, +Met or -Met; total and polysome fraction of Gcn2-/-, +Met or -Met. Each array analysis was done in duplicate.

Dataset Information

Transcription profiling of Arabidopsis polysomal and non-polysomal RNA samples isolated from 10-day-old wild-type and eif3h mutant plants

Publications

On the functions of the h subunit of eukaryotic initiation factor 3 in late stages of translation initiation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure