Does the synthesis of ribosomal RNA take place within nucleolar fibrillar centers or dense fibrillar components?
By means of immunocytochemistry performed on cryosections of cultured cells, RNA polymerase I was localized mainly to nucleolar fibrillar centers. The labelling of nucleolar dense fibrillar components was low and depended on the cell type. In contrast, DNA topoisomerase I and RNP complexes containing U3 snRNA were enriched in dense fibrillar components, their occurrence in fibrillar centers being usually much less.
Raska
I
I
Institute of Experimental Medicine, Czechoslovak Academy of Sciences, Prague.
Reimer
G
G
Jarník
M
M
Kostrouch
Z
Z
Raska
K
K
D000310:Adrenal Gland Neoplasms; D000818:Animals; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism* / Q000648:ultrastructure; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D010673:Pheochromocytoma; D012318:RNA Polymerase I / Q000378:metabolism; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D051381:Rats
D012335:RNA, Ribosomal; D012318:RNA Polymerase I; D004264:DNA Topoisomerases, Type I