SUV39h-independent association of HP1b with fibrillarin-positive nucleolar regions
| Authors | |
|---|---|
| Year of publication | 2010 |
| Type | Article in Periodical |
| Magazine / Source | Chromosoma |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.springerlink.com/content/03353h53h300j70k/ |
| Doi | http://dx.doi.org/10.1007/s00412-009-0252-2 |
| Field | Genetics and molecular biology |
| Keywords | SUV39h; heterochromatin protein 1; nucleoli; cell nucleus |
| Description | Heterochromatin protein 1 (HP1), which binds to sites of histone H3 lysine 9 (H3K9) methylation, is primarily responsible for gene silencing and the formation of heterochromatin. We observed that HP1beta is located in both the chromocenters and fibrillarin-positive nucleoli interiors. However, HP1alfa and HP1gamma occupied fibrillarin-positive compartments to a lesser extent, corresponding to the distinct levels of HP1 subtypes at the promoter of rDNA genes. Deficiency of histone methyltransferases SUV39h, and/or inhibition of histone deacetylases (HDACi) decreased HP1beta and H3K9 trimethylation at chromocenters, but not in fibrillarin-positive regions that co-localized with RNA Pol I. Similarly, SUV39h- and HDACi-dependent nucleolar rearrangement and inhibition of rDNA transcription did not affect the association between HP1beta - and fibrillarin. The presence of HP1beta in nucleoli is likely connected with transcription of ribosomal genes and with the role of fibrillarin in nucleolar processes. |
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