title: trans-splicing of transcripts for the chloroplast psaA1 gene. In vivo requirement for nuclear gene products.
abstract: Photosystem I-deficient Chlamydomonas reinhardtii mutants M18 and F27 lack mature mRNA for the psaA1 gene of photosystem I but accumulate unspliced and partially spliced psaA1 transcripts. Analysis of these transcripts indicate that 1) exon 1 of psaA1 is transcribed separately from exon 2, 2) exon 2 is cotranscribed with the psbD gene, and 3) at least two nuclear gene products are required for exon 1-exon 2 trans-splicing. In addition, analysis of chloroplast transcription in permeabilized cells shows that exon 3 is near the 5' end of a separate transcription unit, indicating that exon 2-exon 3 ligation also occurs by a trans-splicing mechanism.
mesh_terms: D015152:Blotting, Northern; D002467:Cell Nucleus / Q000378:metabolism*; D002696:Chlamydomonas / Q000235:genetics*; D002734:Chlorophyll / Q000235:genetics*; D002736:Chloroplasts / Q000378:metabolism*; D004274:DNA, Recombinant / Q000378:metabolism*; D005091:Exons; D005796:Genes; D007438:Introns; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004274:DNA, Recombinant; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D010940:Plant Proteins; D012333:RNA, Messenger; D002734:Chlorophyll