- THIS ARTICLE
- Full Text
- Full Text (PDF)
- Alert me when this article is cited
- Alert me if a correction is posted
- SERVICES
- Similar articles in this journal
- Similar articles in PubMed
- Alert me to new issues of the journal
- Download to citation manager
- Reprints & Permissions
- CITING ARTICLES
- Citing Articles via HighWire
- GOOGLE SCHOLAR
- Articles by Zimmer, S. L.
- Articles by Stern, D. B.
- PUBMED
- PubMed Citation
- Articles by Zimmer, S. L.
- Articles by Stern, D. B.
Genetics, Vol. 179, 125-136, May 2008, Copyright © 2008
doi:10.1534/genetics.107.086223
Genome-Based Analysis of Chlamydomonas reinhardtii Exoribonucleases and Poly(A) Polymerases Predicts Unexpected Organellar and Exosomal Features
Sara L. Zimmer*,
Zhangjun Fei
,
and
David B. Stern,1
Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, * Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853 and USDA Plant, Soil, and Nutrition Laboratory, Ithaca, New York 14853
1 Corresponding author: Boyce Thompson Institute at Cornell University, Tower Rd., Ithaca, NY 14853.
E-mail: ds28{at}cornell.edu
Enzymes from several gene families modify RNA molecules at their extremities. These reactions occur in several cellular compartments and affect every class of RNA. To assess the diversity of a subclass of these enzymes, we searched Chlamydomonas for open reading frames (ORFs) potentially encoding exoribonucleases, poly(A) polymerases, and proteins known to associate with and/or regulate them. The ORFs were further analyzed for indications of protein localization to the nucleus, cytosol, mitochondrion, and/or chloroplast. By comparing predicted proteins with homologs in Arabidopsis and yeast, we derived several tentative conclusions regarding RNA 5'- and 3'-end metabolism in Chlamydomonas. First, the alga possesses only one each of the following likely organellar enzymes: polynucleotide phosphorylase, hydrolytic exoribonuclease, poly(A) polymerase, and CCA transferase, a surprisingly small complement. Second, although the core of the nuclear/cytosolic exosome decay complex is well conserved, neither nucleus-specific activators nor the cytosolic exosome activators are present. Finally, our discovery of nine noncanonical poly(A) polymerases, a divergent family retaining the catalytic domains of conventional poly(A) polymerases, leads to the hypothesis that polyadenylation may play an especially important regulatory role throughout the Chlamydomonas cell, stabilizing some transcripts and targeting degradation machinery to others.
This article has been cited by other articles:
 |
|
 |
|
  O. Vallon and S. Dutcher Treasure Hunting in the Chlamydomonas Genome Genetics, May 1, 2008; 179(1): 3 - 6. [Full Text] [PDF]
|
|