PML-CONTAINING NUCLEAR-BODIES - THEIR SPATIAL-DISTRIBUTION IN RELATION TO OTHER NUCLEAR-COMPONENTS

Citation
Ma. Grande et al., PML-CONTAINING NUCLEAR-BODIES - THEIR SPATIAL-DISTRIBUTION IN RELATION TO OTHER NUCLEAR-COMPONENTS, Journal of cellular biochemistry, 63(3), 1996, pp. 280-291
Citations number
56
Categorie Soggetti
Biology,"Cell Biology
ISSN journal
07302312
Volume
63
Issue
3
Year of publication
1996
Pages
280 - 291
Database
ISI
SICI code
0730-2312(1996)63:3<280:PN-TSI>2.0.ZU;2-U
Abstract
The PML protein is a human growth suppressor concentrated in 10 to 20 nuclear bodies per nucleus (PML bodies). Disruption of the PML gene ha s been shown to be related to acute promyelocytic leukaemia (APL). To obtain information about the function of PML bodies we have investigat ed the 3D-distribution of PML bodies in the nucleus of T24 cells and c ompared it with the spatial distribution of a variety of other nuclear components, using fluorescence dual-labeling immunocytochemistry and confocal microscopy. Results show that PML bodies are not enriched in nascent RNA, the splicing component U2-snRNP, or transcription factors (glucocorticoid receptor, TFIIH, and E2F). These results show that PM L bodies are not prominent sites of RNA synthesis or RNA splicing. We found that a large fraction of PML bodies (50 to 80%) is closely assoc iated with DNA replication domains during exclusively middle-late S-ph ase. Furthermore, in most cells that we analysed we found at least one PML body was tightly associated with a coiled body. In the APL cell l ine NB4, the PML gene is fused with the RAR alpha gene due to a chromo somal rearrangement. PML bodies have disappeared and the PML antigen, i.e., PML and the PML-RAR fusion protein, is dispersed in a punctated pattern throughout the nucleoplasm. We showed that in NB4 cells the si tes that are rich in PML antigen significantly colocalize with sites a t which nascent RNA accumulates. This suggests that, in contrast to no n-APL cells, in NB4 cells the PML antigen is associated with sites of transcription. The implications of these findings for the function of PML bodies are consistent with the idea that PML bodies are associated with specific genomic loci. (C) 1996 Wiley-Liss, Inc.