Distinctive interactions of the Arabidopsis homolog of the 30 kD subunit of the cleavage and polyadenylation specificity factor (AtCPSF30) with other polyadenylation factor subunits

Suryadevara Rao,Randy D Dinkins,Arthur G Hunt

doi:10.1186/1471-2121-10-51

Suryadevara Rao, Randy D Dinkins + Show 1 more

Open Access

PDF Available

https://doi.org/10.1186/1471-2121-10-51

Copy DOI

Export

Save

Cite

Journal: BMC Cell Biology	Publication Date: Jul 2, 2009
Citations: 28	License type: cc-by

Affiliation: University of Kentucky

Abstract
Highlights/Summary
Full-Text PDF
Similar Papers

Abstract

Listen

BackgroundThe Arabidopsis ortholog of the 30 kD subunit of the mammalian Cleavage and Polyadenylation Specificity Factor (AtCPSF30) is an RNA-binding endonuclease that is associated with other Arabidopsis CPSF subunits (orthologs of the 160, 100, and 73 kD subunits of CPSF). In order to further explore the functions of AtCPSF30, the subcellular distribution of the protein was examined by over-expressing fusion proteins containing fluorescent reporters linked to different CPSF subunits.ResultsIt was found that AtCPSF30 by itself localizes, not to the nucleus, but to the cytoplasm. AtCPSF30 could be found in the nucleus when co-expressed with AtCPSF160 or AtCPSF73(I), one of the two Arabidopsis orthologs of CPSF73. This re-directing of AtCPSF30 indicates that AtCPSF30 is retained in the nucleus via interactions with either or both of these other CPSF subunits. Co-expression of AtCSPF30 with AtCPSF100 altered the location, not of AtCPSF30, but rather of AtCPSF100, with these proteins residing in the cytoplasm. Deletion of plant-specific N- or C-terminal domains of AtCPSF30 abolished various of the interactions between AtCPSF30 and other CPSF subunits, suggesting that the plant CPSF complex assembles via novel protein-protein interactions.ConclusionThese results suggest that the nuclear CPSF complex in plants is a dynamic one, and that the interactions between AtCPSF30 and other CPSF subunits are different from those existing in other eukaryotes.

Highlights

The Arabidopsis ortholog of the 30 kD subunit of the mammalian Cleavage and Polyadenylation Specificity Factor (AtCPSF30) is an RNA-binding endonuclease that is associated with other Arabidopsis CPSF subunits
In all of these constructs, expression was under control of the cauliflower mosaic virus 35S promoter; the choice of overexpression using the 35S promoter was based on prior observations indicating that the levels of AtCPSF30 in wild-type plants are exceedingly low [16], and detection of the products of transgenes driven by the promoter from the AtCPSF30 gene (At1g30460) was not feasible
It was expected that this approach would provide information about the inherent subcellular location signals carried by AtCPSF30

Summary

Introduction

The Arabidopsis ortholog of the 30 kD subunit of the mammalian Cleavage and Polyadenylation Specificity Factor (AtCPSF30) is an RNA-binding endonuclease that is associated with other Arabidopsis CPSF subunits (orthologs of the 160, 100, and 73 kD subunits of CPSF). Messenger RNA polyadenylation is mediated by a multifactor complex in eukaryotes. In mammals, this complex consists of the Cleavage Stimulatory Factor (CstF), the Cleavage and Polyadenylation Specificity Factor (CPSF), two Cleavage Factors (CFIm and CFIIm) and poly(A) polymerase [1,2,3]. CPSF binds to the AAUAAA sequence via its 160 kD subunit [4], and CstF recognizes the downstream element via its 64 kD subunit [5,6,7]. Among the more interesting of the subunits of the polyadenylation complex is the 30 kD subunit of CPSF (page number not for citation purposes)

Methods

Results

Discussion

Conclusion