Translational Pausing Ensures Membrane Targeting and Cytoplasmic Splicing of XBP1u mRNA

• DOI: 10.1126/science.1197142
• Publication Date: 2011-01-14T06:16:21Z
• Authors: Kota Yanagitani; Yukio Kimata; Hiroshi Kadokura; Kenji Kohno
• Keywords: Endoribonuclease; P-bodies

Upon endoplasmic reticulum (ER) stress, an endoribonuclease, inositol-requiring enzyme-1α, splices the precursor unspliced form of X-box-binding protein 1 messenger RNA (XBP1u mRNA) on ER membrane to yield active transcription factor (XBP1s), leading alleviation stress. The nascent peptide encoded by XBP1u mRNA drags mRNA-ribosome-nascent chain (R-RNC) complex for efficient cytoplasmic splicing. We found that translation was briefly paused stabilize R-RNC complex. Mutational analysis revealed evolutionarily conserved module at carboxyl terminus responsible translational pausing and required targeting splicing mRNA. Thus, may be used unexpectedly diverse cellular processes in mammalian cells.