About: Termination-dependent reinitiation is used to co-ordinately regulate expression of the M1 and BM2 open-reading frames (ORFs) of the dicistronic influenza B segment 7 RNA. The start codon of the BM2 ORF overlaps the stop codon of the M1 ORF in the pentanucleotide UAA UG and ∼10% of ribosomes terminating at the M1 stop codon reinitiate translation at the overlapping AUG. BM2 synthesis requires the presence of, and translation through, 45 nt of RNA immediately upstream of the UAA UG, known as the ‘termination upstream ribosome binding site’ (TURBS). This region may tether ribosomal 40S subunits to the mRNA following termination and a short region of the TURBS, motif 1, with complementarity to helix 26 of 18S rRNA has been implicated in this process. Here, we provide further evidence for a direct interaction between mRNA and rRNA using antisense oligonucleotide targeting and functional analysis in yeast cells. The TURBS also binds initiation factor eIF3 and we show here that this protein stimulates reinitiation from both wild-type and defective TURBS when added exogenously, perhaps by stabilising ribosome-mRNA interactions. Further, we show that the position of the TURBS with respect to the UAA UG overlap is crucial, and that termination too far downstream of the 18S complementary sequence inhibits the process, probably due to reduced 40S tethering. However, in reporter mRNAs where the restart codon alone is moved downstream, termination-reinitiation is inhibited but not abolished, thus the site of reinitiation is somewhat flexible. Reinitiation on distant AUGs is not inhibited in eIF4G-depleted RRL, suggesting that the tethered 40S subunit can move some distance without a requirement for linear scanning.   Goto Sponge  NotDistinct  Permalink

An Entity of Type : fabio:Abstract, within Data Space : covidontheweb.inria.fr associated with source document(s)

AttributesValues
type
value
  • Termination-dependent reinitiation is used to co-ordinately regulate expression of the M1 and BM2 open-reading frames (ORFs) of the dicistronic influenza B segment 7 RNA. The start codon of the BM2 ORF overlaps the stop codon of the M1 ORF in the pentanucleotide UAA UG and ∼10% of ribosomes terminating at the M1 stop codon reinitiate translation at the overlapping AUG. BM2 synthesis requires the presence of, and translation through, 45 nt of RNA immediately upstream of the UAA UG, known as the ‘termination upstream ribosome binding site’ (TURBS). This region may tether ribosomal 40S subunits to the mRNA following termination and a short region of the TURBS, motif 1, with complementarity to helix 26 of 18S rRNA has been implicated in this process. Here, we provide further evidence for a direct interaction between mRNA and rRNA using antisense oligonucleotide targeting and functional analysis in yeast cells. The TURBS also binds initiation factor eIF3 and we show here that this protein stimulates reinitiation from both wild-type and defective TURBS when added exogenously, perhaps by stabilising ribosome-mRNA interactions. Further, we show that the position of the TURBS with respect to the UAA UG overlap is crucial, and that termination too far downstream of the 18S complementary sequence inhibits the process, probably due to reduced 40S tethering. However, in reporter mRNAs where the restart codon alone is moved downstream, termination-reinitiation is inhibited but not abolished, thus the site of reinitiation is somewhat flexible. Reinitiation on distant AUGs is not inhibited in eIF4G-depleted RRL, suggesting that the tethered 40S subunit can move some distance without a requirement for linear scanning.
Subject
  • RNA
  • Genetics
  • Gene expression
  • RNA splicing
  • Molecular biology
  • Molecular genetics
  • Protein biosynthesis
  • Fungus common names
  • Eukaryote genetics
part of
is abstract of
is hasSource of
Faceted Search & Find service v1.13.91 as of Mar 24 2020


Alternative Linked Data Documents: Sponger | ODE     Content Formats:       RDF       ODATA       Microdata      About   
This material is Open Knowledge   W3C Semantic Web Technology [RDF Data]
OpenLink Virtuoso version 07.20.3229 as of Jul 10 2020, on Linux (x86_64-pc-linux-gnu), Single-Server Edition (94 GB total memory)
Data on this page belongs to its respective rights holders.
Virtuoso Faceted Browser Copyright © 2009-2024 OpenLink Software