Simultaneous assessment of the effects of exonic mutations on RNA splicing and protein functions.
To simultaneously assess the effects of exonic mutations on RNA splicing and protein functions, we report here an intron-inclusive cDNA (Intinc) expression system. As a test model, twenty-four mutations in exon 9 of the phenylalanine hydroxylase (PAH) gene were examined in an Intinc expression plasmid composed of the PAH cDNA with the exon 9 flanked by its authentic introns. When the PAH enzyme activities from the Intinc plasmid-transfected cells were compared to those of a standard cDNA expression system, five mutations resulted in significant relative differences in PAH activities attributed to altered exon 9-inclusive mRNA levels. Two of the mutations affected exon recognition probably through splice site modifications and the remaining three affected experimentally verified exon splicing enhancer (ESE) motifs. The Intinc expression system allows not only a better link between mutation genotype to disease phenotype but also contributes to further understanding of molecular mechanisms of deleterious effects of mutations.
Ho
Po-yi
PY
Faculty of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan.
Huang
Miao-Zeng
MZ
Fwu
Victor Tramjay
VT
Lin
Sheng-Chieh
SC
Hsiao
Kwang-Jen
KJ
Su
Tsung-Sheng
TS
D004252:DNA Mutational Analysis / Q000379:methods*; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons; D005838:Genotype; D006801:Humans; D007438:Introns; D009154:Mutation; D010641:Phenotype; D010651:Phenylalanine Hydroxylase / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing
D018076:DNA, Complementary; D010651:Phenylalanine Hydroxylase