TY - JOUR
T1 - Transcription of mouse rDNA is regulated by an activated subform of RNA polymerase I
AU - Tower, John
AU - Sollner-Webb, Barbara
N1 - Funding Information:
We are indebted to Dr. Kathleen Rose for generously providing the rabbit anti-polymerase I and control antibodies and for invaluable discussions about polymerase purification. We also greatly thank Drs. Kevin Sullivan and Eng Tan for generously providing the human autoimmune anti-polymerase I and control IgGs. We gratefully acknowledge Dr. Loris Baggetto for providing the Ehrlich Ascites cell line and for advice on the propagation of these cells, Dw. Valeria Culotta and Aubrey Thompson for helpful discussions, Ms. Susan Kass for DNA cellulose gradient fractions, and Ms. Maria lsern for expert technical assistance. We also thank Ms. Sue Millionie for patient help in preparing this manuscript. This research was supported by grant GM27720 from the National institutes of Health.
PY - 1987/9/11
Y1 - 1987/9/11
N2 - We have identified the species-nonspecific factor required for mouse rDNA transcription, factor C, as an activated subform of RNA polymerase I. C is an RNA polymerase I since it copurifies with bulk polymerase I activity on the three chromatographic columns used to achieve a virtually homogenous preparation of polymerase I, as well as on four additional matrices; it is quantitatively neutralized as well as immunoprecipitated by two different types of anti-polymerase I antibodies; and it has thermal lability identical to that of bulk polymerase I. However, C is clearly distinct from bulk polymerase I in its ability to participate in the stable rDNA transcription complex and to catalyze accurate initiation of rRNA synthesis. It also has a greater sedimentation coefficient than bulk polymerase I. Furthermore, this activated polymerase subform is specifically lacking in extracts of cells in which rDNA transcription was down-regulated because of cycloheximide treatment or attainment of stationary phase. These data suggest that regulation of rDNA transcription in vivo may involve modulation in availability of the activated polymerase I subform.
AB - We have identified the species-nonspecific factor required for mouse rDNA transcription, factor C, as an activated subform of RNA polymerase I. C is an RNA polymerase I since it copurifies with bulk polymerase I activity on the three chromatographic columns used to achieve a virtually homogenous preparation of polymerase I, as well as on four additional matrices; it is quantitatively neutralized as well as immunoprecipitated by two different types of anti-polymerase I antibodies; and it has thermal lability identical to that of bulk polymerase I. However, C is clearly distinct from bulk polymerase I in its ability to participate in the stable rDNA transcription complex and to catalyze accurate initiation of rRNA synthesis. It also has a greater sedimentation coefficient than bulk polymerase I. Furthermore, this activated polymerase subform is specifically lacking in extracts of cells in which rDNA transcription was down-regulated because of cycloheximide treatment or attainment of stationary phase. These data suggest that regulation of rDNA transcription in vivo may involve modulation in availability of the activated polymerase I subform.
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U2 - 10.1016/0092-8674(87)90514-9
DO - 10.1016/0092-8674(87)90514-9
M3 - Article
C2 - 3621348
AN - SCOPUS:0023651269
SN - 0092-8674
VL - 50
SP - 873
EP - 883
JO - Cell
JF - Cell
IS - 6
ER -