RESUMEN
DNA methyltransferase 3-like (DNMT3L) is one of the key players in de novo DNA methylation of imprinting control elements and retrotransposons, which occurs after genome-wide epigenetic erasure during germ cell development. In this review, we summarise the biochemical properties of DNMT3L and discuss the possible mechanisms behind DNMT3L-mediated imprinting establishment and retrotransposon silencing in germ cells. We also discuss possible connections between DNMT3L and non-coding RNA-mediated epigenetic remodelling, the roles of DNMT3L in germ cell development and the implications in stem cell and cancer research.
Asunto(s)
ADN (Citosina-5-)-Metiltransferasas/metabolismo , Epigénesis Genética , Genoma , Células Germinativas/enzimología , Retroelementos/genética , Animales , ADN (Citosina-5-)-Metiltransferasas/genética , Metilación de ADN , Impresión Genómica , Células Germinativas/citología , Células Germinativas/crecimiento & desarrollo , Histona Desacetilasas/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Ratones , Neoplasias/enzimología , Neoplasias/patología , Células Madre/citología , Células Madre/enzimologíaRESUMEN
BACKGROUND: Human herpesvirus 8 (HHV-8), a gamma-herpesvirus, is associated with Kaposi's sarcoma (KS). A variety of assays for the diagnosis HHV-8 infection have been developed. However, the accuracy of current HHV-8 antibody testing is uncertain, mainly in patients with asymptomatic HHV-8 infection. METHODS: We utilized a new immunoblot assay, comprised of three recombinant HHV-8 encoded proteins (ORF16, ORF57, and ORF71) to determine the seroprevalence of HHV-8 in Taiwan. ORF16 encodes a Bcl-2 homologue and is expressed only in the lytic cycle. ORF57 is an immediate-early gene product and can activate gene expression by a post-transcriptional mechanism. ORF71 encodes a viral FLICE inhibitory protein and is a latently expressed protein. We collected 6 KS(+)/HIV(-) patients, 10 KS(-)/HIV(+) individuals, 174 blood donors, and 62 non-KS cancer patients in this study. RESULTS: Among the different populations, ORF57 showed highest reactivities. The frequency of positive results for KS(+)/HIV(-), KS(-)/HIV(+), blood donors, and non-KS cancer patients were 83.3%, 40%, 23%, and 12.9%, respectively. Compared to the widely used lytic immunofluorescence assay, our immunoblotting assay using ORF57 showed higher reactivities among the blood donors. CONCLUSIONS: ORF57 is useful for the detection of HHV-8 infection, especially during the asymptomatic infections.