|
 |
|
|
| The EMBO Journal
(2001) 20, 2742–2756, doi:10.1093/emboj/20.11.2742 |
|
| SKP1–SnRK protein kinase interactions mediate proteasomal binding of a plant SCF ubiquitin ligase |
|
|
| Rosa Farrás1, Alejandro Ferrando1, Ján Jásik1, 2, Tatjana Kleinow1, László Ökrész3, Antonio Tiburcio4, Klaus Salchert5, Carlos del Pozo6, Jeff Schell1 and Csaba Koncz1, 3 |
|
|
1 Max-Planck Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, D-50829 Cologne, Germany 2 Department of Plant Physiology, Comenius University, Mlynska dolina B2, 84215 Bratislava, Slovakia 3 Institute of Plant Biology, Biological Research Center of Hungarian Academy of Sciences, H-6701 Szeged, Temesvári krt. 62, Hungary 4 Unitat de Fisiologia Vegetal, Universitat de Barcelona, Diagonal 643, 08028 Barcelona, Spain 5 Risoe National Laboratory, Plant Biology and Biogeochemistry Department, DK-4000 Roskilde, Denmark 6 Centro de Biologia Molecular 'Severo Ochoa', Cantoblanco, 28049 Madrid, Spain To whom correspondence should be addressed Csaba Koncz, koncz@mpiz-koeln.mpg.de Received 25 September 2000; Revised 27 March 2001; Accepted 12 April 2001. |
|
|
|
| Abstract |
|
Arabidopsis Snf1-related protein kinases (SnRKs) are implicated in pleiotropic regulation of metabolic, hormonal and stress responses through their interaction with the kinase inhibitor PRL1 WD-protein. Here we show that SKP1/ASK1, a conserved SCF (Skp1-cullin-F-box) ubiquitin ligase subunit, which suppresses the skp1-4 mitotic defect in yeast, interacts with the PRL1-binding C-terminal domains of SnRKs. The same SnRK domains recruit an SKP1/ASK1-binding proteasomal protein,  4/PAD1, which enhances the formation of a trimeric SnRK complex with SKP1/ASK1 in vitro. By contrast, PRL1 reduces the interaction of SKP1/ASK1 with SnRKs. SKP1/ASK1 is co-immunoprecipitated with a cullin SCF subunit (AtCUL1) and an SnRK kinase, but not with PRL1 from Arabidopsis cell extracts. SKP1/ASK1, cullin and proteasomal -subunits show nuclear co-localization in differentiated Arabidopsis cells, and are observed in association with mitotic spindles and phragmoplasts during cell division. Detection of SnRK in purified 26S proteasomes and co-purification of epitope- tagged SKP1/ASK1 with SnRK, cullin and proteasomal -subunits indicate that the observed protein interactions between SnRK, SKP1/ASK1 and 4/PAD1 are involved in proteasomal binding of an SCF ubiquitin ligase in Arabidopsis. |
|
| Keywords: Arabidopsis Pleiotropic Regulatory Locus 1 (PRL1), proteasome, SCF ubiquitin ligase, SKP1, ASK1, Snf1-related protein kinase |
|
|
| |
| |
| |
 | Email link to a friend |
| |
 | Download PDF |
| |
 | Full text |
| |
| |
| |
 | Next article |
| |
 | Previous article |
| |
 | Table of contents |
| |
| |
 | Rights and permissions |
| |
 | Reprints |
| |
| |
| |
 Register for table of contents by email | |
| |
| |
| |
