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Target specificity among canonical nuclear poly(A) polymerases in plants modulates organ growth and pathogen response.

Authors :
Son Lang Vi
Trost, Gerda
Lange, Peggy
Czesnick, Hjördis
Rao, Nishta
Lieber, Diana
Laux, Thomas
Gray, William M.
Manley, James L.
Groth, Detlef
Kappel, Christian
Lenhard, Michael
Source :
Proceedings of the National Academy of Sciences of the United States of America. 8/20/2013, Vol. 110 Issue 34, p13994-13999. 6p.
Publication Year :
2013

Abstract

Polyadenylation of pre-mRNAs is critical for efficient nuclear export, stability, and translation of the mature mRNAs, and thus for gene expression. The bulk of pre-mRNAs are processed by canonical nuclear poly(A) polymerase (PAPS). Both vertebrate and higher-plant genomes encode more than one isoform of this enzyme, and these are coexpressed in different tissues. However, in neither case is it known whether the isoforms fulfill different functions or polyadenylate distinct subsets of pre-mRNAs. Here we show that the three canonical nuclear PAPS isoforms in Arabidopsis are functionally specialized owing to their evolutionarily divergent C-terminal domains. A strong loss-of-function mutation in PAPS1 causes a male gametophytic defect, whereas a weak allele leads to reduced leaf growth that results in part from a constitutive pathogen response. By contrast, plants lacking both PAPS2 and PAPS4 function are viable with wild-type leaf growth. Polyadenylation of SMALL AUXIN UP RNA (SAUR) mRNAs depends specifically on PAPS1 function. The resulting reduction in SAUR activity in paps1 mutants contributes to their reduced leaf growth, providing a causal link between polyadenylation of specific pre-mRNAs by a particular PAPS isoform and plant growth. This suggests the existence of an additional layer of regulation in plant and possibly vertebrate gene expression, whereby the relative activities of canonical nuclear PAPS isoforms control de novo synthesized poly(A) tail length and hence expression of specific subsets of mRNAs. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00278424
Volume :
110
Issue :
34
Database :
Academic Search Index
Journal :
Proceedings of the National Academy of Sciences of the United States of America
Publication Type :
Academic Journal
Accession number :
89901291
Full Text :
https://doi.org/10.1073/pnas.1303967110