Mapping of branchpoint nucleotides in mutant pre-mRNAs expressed in plant cells

Plant J. 1996 Mar;9(3):381-9. doi: 10.1046/j.1365-313x.1996.09030381.x.


Pre-mRNA encoding rubisco activase in the Arabidopsis thaliana mutant rca contains a GU to AU change at the 5' splice site of intron 3 and this mutation results in accumulation of splicing intermediates bearing an incompletely processed intron. It has been demonstrated that one of the intermediates contains intron 3 in the form of a lariat and the branchpoint nucleotide has been mapped to the A residue at position -32 forming part of the sequence UUGAU. Analysis of a similar GU to AU 5' splice site mutation, present in a synthetic pre-mRNA context expressed in transfected protoplasts of Nicotiana plumbaginifolia, also suggests formation of lariats with branching occurring at A-31. A small fraction (approximately 10%) of this mutant pre-mRNA also underwent the second step of splicing. In addition to the consensus AG, an AU dinucleotide was used as splicing acceptor.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Base Sequence
  • Chromosome Mapping
  • DNA Primers / genetics
  • DNA, Plant / genetics
  • Introns
  • Molecular Sequence Data
  • Mutation
  • Plant Proteins*
  • Plants, Genetically Modified
  • Plants, Toxic
  • RNA Precursors / genetics*
  • RNA Precursors / metabolism
  • RNA Splicing
  • RNA, Plant / genetics*
  • RNA, Plant / metabolism
  • Ribulose-Bisphosphate Carboxylase / genetics
  • Tobacco / genetics


  • DNA Primers
  • DNA, Plant
  • Plant Proteins
  • RNA Precursors
  • RNA, Plant
  • rca protein, plant
  • Ribulose-Bisphosphate Carboxylase