![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
KE McGrath, JF Smothers, CA Dadd, MT Madireddi, MA Gorovsky and CD Allis
Department of Biology, University of Rochester, New York 14627, USA.
An abundant 52-kDa phosphoprotein was identified and characterized from macronuclei of the ciliated protozoan Tetrahymena thermophila. Immunoblot analyses combined with light and electron microscopic immunocytochemistry demonstrate that this polypeptide, termed Nopp52, is enriched in the nucleoli of transcriptionally active macronuclei and missing altogether from transcriptionally inert micronuclei. The cDNA sequence encoding Nopp52 predicts a polypeptide whose amino-terminal half consists of multiple acidic/serine-rich regions alternating with basic/proline-rich regions. Multiple serines located in these acidic stretches lie within casein kinase II consensus motifs, and Nopp52 is an excellent substrate for casein kinase II in vitro. The carboxyl- terminal half of Nopp52 contains two RNA recognition motifs and an extreme carboxyl-terminal domain rich in glycine, arginine, and phenylalanine, motifs common in many RNA processing proteins. A similar combination and order of motifs is found in vertebrate nucleolin and yeast NSR1, suggesting that Nopp52 is a member of a family of related nucleolar proteins. NSR1 and nucleolin have been implicated in transcriptional regulation of rDNA and rRNA processing. Consistent with a role in ribosomal gene metabolism, rDNA and Nopp52 colocalize in situ, as well as by cross-linking and immunoprecipitation experiments, demonstrating an association between Nopp52 and rDNA in vivo.
This article has been cited by other articles:
|
|
 |
|
  J. Bednenko, T. Noto, L. V. DeSouza, K. W. M. Siu, R. E. Pearlman, K. Mochizuki, and M. A. Gorovsky Two GW Repeat Proteins Interact with Tetrahymena thermophila Argonaute and Promote Genome Rearrangement Mol. Cell. Biol., September 15, 2009; 29(18): 5020 - 5030. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. Cervantes, R. S. Coyne, X. Xi, and M.-C. Yao The Condensin Complex Is Essential for Amitotic Segregation of Bulk Chromosomes, but Not Nucleoli, in the Ciliate Tetrahymena thermophila Mol. Cell. Biol., June 15, 2006; 26(12): 4690 - 4700. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H Ginisty, H Sicard, B Roger, and P Bouvet Structure and functions of nucleolin J. Cell Sci., January 3, 1999; 112(6): 761 - 772. [Abstract] [PDF]
|
|
|
|
 |
|
 H. Huang, E. A. Wiley, C. R. Lending, and C. D. Allis An HP1-like protein is missing from transcriptionally silent micronuclei of Tetrahymena PNAS, November 10, 1998; 95(23): 13624 - 13629. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Das, J. Park, C. Hagen, and M Parsons Distinct domains of a nucleolar protein mediate protein kinase binding, interaction with nucleic acids and nucleolar localization J. Cell Sci., January 9, 1998; 111(17): 2615 - 2623. [Abstract] [PDF]
|
|
|
|
 |
|
 J. Smothers, C. Mizzen, M. Tubbert, R. Cook, and C. Allis Pdd1p associates with germline-restricted chromatin and a second novel anlagen-enriched protein in developmentally programmed DNA elimination structures Development, January 11, 1997; 124(22): 4537 - 4545. [Abstract] [PDF]
|
|
