Neurospora importin α is required for normal heterochromatic formation and DNA methylation.
| Autor: | Andrew D Klocko, Michael R Rountree, Paula L Grisafi, Shan M Hays, Keyur K Adhvaryu, Eric U Selker |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | PLoS Genetics, Vol 11, Iss 3, p e1005083 (2015) |
| Druh dokumentu: | article |
| ISSN: | 1553-7390 1553-7404 69440182 |
| DOI: | 10.1371/journal.pgen.1005083 |
| Popis: | Heterochromatin and associated gene silencing processes play roles in development, genome defense, and chromosome function. In many species, constitutive heterochromatin is decorated with histone H3 tri-methylated at lysine 9 (H3K9me3) and cytosine methylation. In Neurospora crassa, a five-protein complex, DCDC, catalyzes H3K9 methylation, which then directs DNA methylation. Here, we identify and characterize a gene important for DCDC function, dim-3 (defective in methylation-3), which encodes the nuclear import chaperone NUP-6 (Importin α). The critical mutation in dim-3 results in a substitution in an ARM repeat of NUP-6 and causes a substantial loss of H3K9me3 and DNA methylation. Surprisingly, nuclear transport of all known proteins involved in histone and DNA methylation, as well as a canonical transport substrate, appear normal in dim-3 strains. Interactions between DCDC members also appear normal, but the nup-6(dim-3) allele causes the DCDC members DIM-5 and DIM-7 to mislocalize from heterochromatin and NUP-6dim-3 itself is mislocalized from the nuclear envelope, at least in conidia. GCN-5, a member of the SAGA histone acetyltransferase complex, also shows altered localization in dim-3, raising the possibility that NUP-6 is necessary to localize multiple chromatin complexes following nucleocytoplasmic transport. |
| Databáze: | Directory of Open Access Journals |
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