Intron retention: a human DKC1 gene common splicing event.
Identification of alternatively spliced transcripts produced by a gene is a crucial step in deciphering the bulk of its biological roles and the overall processes that regulate its activity. By using a combination of bioinformatic and molecular approaches we identified, cloned, and characterized 3 novel alternative splice isoforms derived from human dyskeratosis congenita 1 (hDKC1), an essential human gene causative of the X-linked dyskeratosis congenita disease and involved in multiple functions related to cell growth, proliferation, and telomere maintenance. Expression of the new isoforms, all characterized by intron retention, was confirmed by RT-PCR in a panel of diverse cell lines and normal human tissues, and despite the presence of premature termination codons, was not down-regulated by the mechanism of nonsense-mediated decay. Accumulation of these transcripts fluctuated distinctly in the diverse tissues and during in vitro differentiation of Caco2 cells, suggesting that their ratio may contribute to the gene functional diversity across different cell types. Intriguingly, the structure of one isoform leads to exonize an intronically encoded small nucleolar RNA (snoRNA), highlighting an additional layer of complexity that can contribute to overall gene regulation.
Dipartimento di Biologia, Complesso Universitario di Monte S. Angelo, Università di Napoli "Federico II", via Cinthia, 80126 Napoli, Italia.
Mimmo
M
Turano
Alberto
A
Angrisani
Nunzia
N
Di Maio
Maria
M
Furia
D017398:Alternative Splicing; D018938:Caco-2 Cells; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D018389:Codon, Nonsense; D019871:Dyskeratosis Congenita / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D005786:Gene Expression Regulation; D014644:Genetic Variation; D006801:Humans; D007438:Introns; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D020537:RNA, Small Nucleolar / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
D018797:Cell Cycle Proteins; D018389:Codon, Nonsense; C112148:DKC1 protein, human; D009687:Nuclear Proteins; D020033:Protein Isoforms; D020537:RNA, Small Nucleolar