Reference: Schwer B, et al. (2004) Portability and fidelity of RNA-repair systems. Proc Natl Acad Sci U S A 101(9):2788-93

Reference Help

Abstract


Yeast tRNA ligase (Trl1) is an essential enzyme that converts cleaved tRNA half-molecules into spliced tRNAs containing a 2'-PO(4), 3'-5' phosphodiester at the splice junction. Trl1 also catalyzes splicing of HAC1 mRNA during the unfolded protein response. Trl1 performs three reactions: the 2',3'-cyclic phosphate of the proximal RNA fragment is hydrolyzed to a 3'-OH, 2'-PO(4) by a cyclic phosphodiesterase; the 5'-OH of the distal RNA fragment is phosphorylated by a GTP-dependent polynucleotide kinase; and the 3'-OH, 2'-PO(4), and 5'-PO(4) ends are then sealed by an ATP-dependent RNA ligase. The removal of the 2'-PO(4) at the splice junction is catalyzed by the essential enzyme Tpt1, which transfers the RNA 2'-PO(4) to NAD(+) to form ADP-ribose 1"-2"-cyclic phosphate. Here, we show that the bacteriophage T4 enzymes RNA ligase 1 and polynucleotide kinase/phosphatase can fulfill the tRNA and HAC1 mRNA splicing functions of yeast Trl1 in vivo and bypass the requirement for Tpt1. These results attest to the portability of RNA-repair systems, notwithstanding the significant differences in the specificities, mechanisms, and reaction intermediates of the individual yeast and T4 enzymes responsible for the RNA healing and sealing steps. We surmise that Tpt1 and its unique metabolite ADP-ribose 1"-2"-cyclic phosphate do not play essential roles in yeast independent of the tRNA-splicing reaction. Our finding that one-sixth of spliced HAC1 mRNAs in yeast cells containing the T4 RNA-repair system suffered deletion of a single nucleotide at the 3' end of the splice-donor site suggests a model whereby the yeast RNA-repair system evolved a requirement for the 2'-PO(4) for RNA ligation to suppress inappropriate RNA recombination.

Reference Type
Journal Article
Authors
Schwer B, Sawaya R, Ho CK, Shuman S
Primary Lit For
Additional Lit For
Review For

Interaction Annotations


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Type Assay Annotation Action Modification Phenotype Source Reference

Gene Ontology Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Gene Ontology Term Qualifier Aspect Method Evidence Source Assigned On Annotation Extension Reference

Phenotype Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Regulation Annotations


Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Experiment Assay Construct Conditions Strain Background Reference