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The splicing of U12-type introns can be a rate-limiting step in gene expression.

ABSTRACT: Some protein-coding genes in metazoan genomes contain a minor class of introns that are excised by a distinct, low-abundance spliceosome. We have developed a quantitative RT-PCR assay that allows comparison of the relative rates of intron removal from the transcripts present in a pre-mRNA population. We show that the U12-type introns are more slowly spliced than the major-class (U2-type) introns from three endogenous pre-mRNAs in human tissue culture cells. In Drosophila melanogaster S2 cells, using minigene constructs designed to produce nearly identical mRNAs, we observe increased expression of fluorescent protein and mature mRNA upon mutation of a U12-type to a U2-type intron. These results provide evidence that the level of gene expression in vivo is lowered by the presence of a U12-type intron and implicate the U12-type spliceosome as a target in the post-transcriptional regulation of gene expression.

SUBMITTER: Patel AA

PROVIDER: S-EPMC126102 | biostudies-literature | 2002 Jul

REPOSITORIES: biostudies-literature

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The splicing of U12-type introns can be a rate-limiting step in gene expression.

Patel Abhijit A AA McCarthy Matthew M Steitz Joan A JA

The EMBO journal 20020701 14

Some protein-coding genes in metazoan genomes contain a minor class of introns that are excised by a distinct, low-abundance spliceosome. We have developed a quantitative RT-PCR assay that allows comparison of the relative rates of intron removal from the transcripts present in a pre-mRNA population. We show that the U12-type introns are more slowly spliced than the major-class (U2-type) introns from three endogenous pre-mRNAs in human tissue culture cells. In Drosophila melanogaster S2 cells, u ...[more]

PMID: 12110592

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Regulation of gene expression through inefficient splicing of U12-type introns.

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Alternative splicing and bioinformatic analysis of human U12-type introns.

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Evolutionary dynamics of U12-type spliceosomal introns.

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U12 type introns were lost at multiple occasions during evolution.

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Branchpoint selection in the splicing of U12-dependent introns in vitro.

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| S-EPMC3630739 | biostudies-literature

Aberrant splicing of U12-type introns is the hallmark of ZRSR2 mutant myelodysplastic syndrome

Project description:Somatic mutations in the spliceosome gene ZRSR2 (located on the X chromosome) are associated with myelodysplastic syndrome (MDS). ZRSR2 is involved in the recognition of 3' splice site during the early stages of spliceosome assembly; however, its precise role in RNA splicing has remained unclear. Here, we characterize ZRSR2 as an essential component of the minor spliceosome (U12-dependent) assembly. shRNA mediated knockdown of ZRSR2 leads to impaired splicing of the U12-type introns, and RNA-Sequencing of MDS bone marrow reveals that loss of ZRSR2 activity causes increased mis-splicing. These splicing defects involve retention of the U12-type introns while splicing of the U2-type introns remain mostly unaffected. ZRSR2 deficient cells also exhibit reduced proliferation potential and distinct alterations in myeloid and erythroid differentiation in vitro. These data identify a specific role for ZRSR2 in RNA splicing and highlight dysregulated splicing of U12-type introns as a characteristic feature of ZRSR2 mutations in MDS. RNA sequencing was performed on 16 bone marrow samples (MDS and normal) and six samples of control or ZRSR2 shRNA transduced TF-1 cells and data was analysed for aberrant splicing caused by ZRSR2 mutations/deficiency.

2015-01-15 | E-GEOD-63816 | biostudies-arrayexpress

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