Polo-like kinase interacts with proteasomes and regulates their activity

Citation
Y. Feng et al., Polo-like kinase interacts with proteasomes and regulates their activity, CELL GROWTH, 12(1), 2001, pp. 29-37
Citations number
42
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
CELL GROWTH & DIFFERENTIATION
ISSN journal
1044-9523 → ACNP
Volume
12
Issue
1
Year of publication
2001
Pages
29 - 37
Database
ISI
SICI code
1044-9523(200101)12:1<29:PKIWPA>2.0.ZU;2-I
Abstract
The polo-like kinase (Plk) has been shown to be associated with the anaphas e-promoting complex at the transition from metaphase to anaphase and to reg ulate ubiquitination, the process that targets proteins for degradation by proteasomes. In this study, we have identified proteasomal proteins interac ting with Plk by mass spectrometry and found that Plk and 20S proteasome su bunits could be reversibly immunoprecipitated from both human CA46 cells an d HEK 293 cells transfected with HA-Plk. Furthermore, both coprecipitated P lk and baculovirus-expressed Plk were able to phosphorylate proteasome subu nits, and metabolic labeling studies indicate that Plk is partially respons ible for the phosphorylation of 20S proteasome subunits C9 and C8 in vivo. In addition, phosphorylation of proteasomes by Plk enhanced proteolytic act ivity toward an artificial substrate Suc-L-L-V-Y-AMC in vitro and in vivo. Finally, we were also able to detect Plk associated with 26S proteasomes un der certain conditions. Together our results suggest that Plk is an importa nt mitotic regulator of proteasome activity.