Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

A cell‐cycle‐regulated kinase activity phosphorylates plant retinoblastoma protein and contains, in Arabidopsis, a CDKA/cyclin D complex

A cell‐cycle‐regulated kinase activity phosphorylates plant retinoblastoma protein and contains,... The activity of cyclin‐dependent kinases (CDK) is crucial for cell‐cycle transitions. Here, we report the identification of a CDK activity that phosphorylates the retinoblastoma‐related (RBR) protein. A CDK/cyclin complex that binds to and phosphorylates RBR may be isolated from various plant sources, e.g. wheat, maize, Arabidopsis thaliana and tobacco, and from cells growing under various conditions. The presence of an RBR‐associated CDK activity correlates with the proliferative activity, suggesting that phosphorylation of RBR is a major event in actively proliferating tissues. In A. thaliana, this activity comprises a PSTAIRE CDKA and at least cyclin D2. Furthermore, this CDK activity is cell‐cycle‐regulated, as revealed by studies with highly synchronized tobacco BY‐2 cells where it is maximal in late G1 and early S phase cells and progressively decreases until G2 phase. Aphidicolin‐arrested but not roscovitine‐arrested cells contain a PSTAIRE‐type CDK that binds to and phosphorylates RBR. Thus, association with a D‐type cyclin is a likely mechanism leading to CDK activation late in G1. Our studies constitute the first report measuring the activity of CDK/cyclin complexes formed in vivo on RBR, an activity that fluctuates in a cell‐cycle‐dependent manner. This work provides the basis for further studies on the impact of phosphorylation of RBR on its function during the cell cycle and development. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Plant Journal Wiley

A cell‐cycle‐regulated kinase activity phosphorylates plant retinoblastoma protein and contains, in Arabidopsis, a CDKA/cyclin D complex

Loading next page...
 
/lp/wiley/a-cell-cycle-regulated-kinase-activity-phosphorylates-plant-mdhxtIRI0S

References (55)

Publisher
Wiley
Copyright
Copyright © 2001 Wiley Subscription Services, Inc., A Wiley Company
ISSN
0960-7412
eISSN
1365-313X
DOI
10.1046/j.1365-313X.2001.01160.x
Publisher site
See Article on Publisher Site

Abstract

The activity of cyclin‐dependent kinases (CDK) is crucial for cell‐cycle transitions. Here, we report the identification of a CDK activity that phosphorylates the retinoblastoma‐related (RBR) protein. A CDK/cyclin complex that binds to and phosphorylates RBR may be isolated from various plant sources, e.g. wheat, maize, Arabidopsis thaliana and tobacco, and from cells growing under various conditions. The presence of an RBR‐associated CDK activity correlates with the proliferative activity, suggesting that phosphorylation of RBR is a major event in actively proliferating tissues. In A. thaliana, this activity comprises a PSTAIRE CDKA and at least cyclin D2. Furthermore, this CDK activity is cell‐cycle‐regulated, as revealed by studies with highly synchronized tobacco BY‐2 cells where it is maximal in late G1 and early S phase cells and progressively decreases until G2 phase. Aphidicolin‐arrested but not roscovitine‐arrested cells contain a PSTAIRE‐type CDK that binds to and phosphorylates RBR. Thus, association with a D‐type cyclin is a likely mechanism leading to CDK activation late in G1. Our studies constitute the first report measuring the activity of CDK/cyclin complexes formed in vivo on RBR, an activity that fluctuates in a cell‐cycle‐dependent manner. This work provides the basis for further studies on the impact of phosphorylation of RBR on its function during the cell cycle and development.

Journal

The Plant JournalWiley

Published: Nov 1, 2001

Keywords: ; ; ; ; ;

There are no references for this article.