Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Genomic evidence for elevated translational efficiency through mRNA looping (#463)

Shaohuan Wu 1
  1. Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, BEIJING, China

mRNA translation is subject to sophisticated control, among which is mRNA looping.mRNA looping is mediated by the loop complex eIF4E-eIF4G-PABP and implied to facilitate translational initiation. Here we performed ribsome profiling in a yeast strain with PABP knocked down, to investigate the translational regulation on a genome-wide scale. We found that translational efficiency decrease is more dramatic in potentially looped mRNAs inferred from a previous RIP-seq study. We further observed that shorter transcripts exhibit more dramatic decrease in translational efficiency in the PABP deficient strain, suggesting that transcript length is potentially a major determinant of the degree of mRNA looping (percentage of looped mRNAs for each mRNA species). To our knowledge, this study presents the first genome-wide evidence that mRNA looping facilitates translation initiation and implicates the possible mechanism of mRNA looping, which potentially explains why ribosome protein coding genes are characterized by incredibly shorter transcript length compared to other genes.