CONICET | Buscador de Institutos y Recursos Humanos

Human Disc large (DLG1) has been demonstrated to be involved in the control of cell polarity and maintenance of tissue architecture, and to be lost in human tumors. However, the mechanisms controlling DLG1 expression are not fully understood. We previously performed the cloning and functional analysis of DLG1 promoter region. Using RACE techniques, we identified an alternative splicing event in the 5 region of DLG1 mRNA that generates transcripts with two different 5-UTRs. We showed, by reporter assays, that the DLG1 5-UTR containing the alternatively-spliced exon interferes with the translation of a downstream ORF, suggesting that this splicing event can contribute to down-regulation of DLG1. We are analyzing the contribution of an ATG codon present in the extra exon, in reducing translation efficiency, by mutagenesis and luciferase assays. By real time RT-PCR and Actinomicyn D treatment we could determine that the short version of DLG1 5UTR makes the transcript more stable. Moreover, bioinformatic analysis of DLG1 promoter revealed the presence of two CpGrich regions compatible with CpG islands. We observed an increase of DLG1 expression by immunoblotting and immunofluorescence in low-level DLG1-expressing cells when treated with the methylase inhibitor 5-aza-2-deoxycytidine. These results might indicate that epigenetic mechanisms may also play a role in DLG1 regulation.  Publicado en Biocell(ISSN 0327-9545) 2009;33 (Supl.):69