Nucleologenesis: U3 snRNA-containing prenucleolar bodies move to sites of active pre-rRNA transcription after mitosis
Por:
Jiménez-García L.F., Segura-Valdez M.D.L., Ochs R.L., Rothblum L.I., Hannan R., Spector D.L.
Publicada:
1 ene 1994
Resumen:
We have investigated the distribution of U3 snRNA and rRNA in HeLa cells and normal rat kidney cells during interphase and mitosis. U3 snRNA, known to be involved in pre-rRNA processing, was detected in nucleoli and coiled bodies during interphase, whereas rRNA was distributed in the nucleoli and throughout the cytoplasm. By comparison, ribosomal protein S6 was detected in nucleoli, coiled bodies, and in the cytoplasm. During nucleologenesis, pre- rRNA was observed in newly forming nucleoli during late telophase but not in prenucleolar bodies (PNBs), whereas U3 snRNA was detected in forming nucleoli and PNBs. Similar findings to those reported here for the localization of U3 snRNA have been reported previously for the U3 small nuclear ribonucleoprotein fibrillarin. These results suggest that components involved in pre-rRNA processing localize to discrete PNBs at the end of mitosis. The nucleolus is formed at specific telophase domains (nucleolar organizing regions) and the PNBs, containing factors essential for pre-rRNA processing, are recruited to these sites of rRNA transcription and processing.
Filiaciones:
Jiménez-García L.F.:
Laboratory of Electron Microscopy, Faculty of Sciences, Natl. Autonomous Univ. of Mexico, Mexico, D.F., Mexico
Segura-Valdez M.D.L.:
Laboratory of Electron Microscopy, Faculty of Sciences, Natl. Autonomous Univ. of Mexico, Mexico, D.F., Mexico
Ochs R.L.:
Scripps Research Institute, San Diego, CA 92037, United States
Rothblum L.I.:
Geisinger Clinic, Weis Center for Research, Danville, PA 17822, United States
Hannan R.:
Geisinger Clinic, Weis Center for Research, Danville, PA 17822, United States
Spector D.L.:
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, United States
Cold Spring Harbor Laboratory, One Bungtown Road, Cold Spring Harbor, NY 11724, United States
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