RT Journal Article
SR Electronic
T1 A Kinetic Framework for a Mammalian RNA Polymerase in Vivo
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1623
OP 1626
DO 10.1126/science.1076164
VO 298
IS 5598
A1 Dundr, Miroslav
A1 Hoffmann-Rohrer, Urs
A1 Hu, Qiyue
A1 Grummt, Ingrid
A1 Rothblum, Lawrence I.
A1 Phair, Robert D.
A1 Misteli, Tom
YR 2002
UL http://science.sciencemag.org/content/298/5598/1623.abstract
AB We have analyzed the kinetics of assembly and elongation of the mammalian RNA polymerase I complex on endogenous ribosomal genes in the nuclei of living cells with the use of in vivo microscopy. We show that components of the RNA polymerase I machinery are brought to ribosomal genes as distinct subunits and that assembly occurs via metastable intermediates. With the use of computational modeling of imaging data, we have determined the in vivo elongation time of the polymerase, and measurements of recruitment and incorporation frequencies show that incorporation of components into the assembling polymerase is inefficient. Our data provide a kinetic and mechanistic framework for the function of a mammalian RNA polymerase in living cells.