PT  - JOURNAL ARTICLE
AU  - Eskiw, Christopher H.
AU  - Rapp, Alexander
AU  - Carter, David R. F.
AU  - Cook, Peter R.
TI  - RNA polymerase II activity is located on the surface of protein-rich transcription factories
AID  - 10.1242/jcs.027250
DP  - 2008 Jun 15
TA  - Journal of Cell Science
PG  - 1999--2007
VI  - 121
IP  - 12
4099  - http://jcs.biologists.org/content/121/12/1999.short
4100  - http://jcs.biologists.org/content/121/12/1999.full
SO  - J. Cell Sci.2008 Jun 15; 121
AB  - We used electron spectroscopic imaging to map nucleoplasmic transcription sites in human cells at unprecedented resolution. HeLa cells were permeabilised, nascent transcripts were extended in BrUTP by ∼40 nucleotides and the resulting BrRNA immunolabelled with gold particles before structures were viewed. Nascent RNA is almost invariably associated with polymorphic and nitrogen-rich (but phosphorus-poor) structures with a diameter of ∼87 nm and mass of 10 MDa (calculated by reference to nucleosomes with known numbers of phosphorus and nitrogen atoms). Structures with similar atomic signatures and diameters were observed using correlative microscopy and in unpermeabilised cells. Our results are consistent with RNA synthesis occurring on the surface of these huge protein-rich transcription factories.