Translation Initiation Factor AteIF(iso)4E Is Involved in Selective mRNA Translation in Arabidopsis Thaliana Seedlings

摘要: One of the most regulated steps translation initiation is recruitment mRNA by machinery. In eukaryotes, this step mediated 5′end cap-binding factor eIF4E bound to bridge protein eIF4G and forming eIF4F complex. plants, different isoforms form antigenically distinct eIF(iso)4F complexes proposed mediate selective translation. Using a microarray analysis polyribosome- non-polyribosome-purified mRNAs from 15 day-old Arabidopsis thaliana wild type [WT] eIF(iso)4E knockout mutant [(iso)4E-1] seedlings we found 79 transcripts shifted polyribosomes toward non-polyribosomes, 47 with opposite behavior in mutant. The translationally decreased were overrepresented root-preferentially expressed genes proteins endomembrane system, including several transporters such as phosphate transporter PHOSPHATE1 (PHO1), Sucrose 3 (SUC3), ABC transporter-like ATPase activity (MRP11) five electron transporters, well signal transduction-, modification- transcription-related proteins. Under normal growth conditions, expression under constitutive promoter 35 S enhanced polyribosomal PHO1 supporting its translational preference for eIF(iso)4E. Furthermore, deficiency, increased overexpressing plants compared type. addition, had larger root, whereas directed caused shorter root but not deficiency. These results indicate that relevant development conditions.