Activity and regulation of the centrosome-associated proteasome

Citation
Rp. Fabunmi et al., Activity and regulation of the centrosome-associated proteasome, J BIOL CHEM, 275(1), 2000, pp. 409-413
Citations number
50
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
00219258 → ACNP
Volume
275
Issue
1
Year of publication
2000
Pages
409 - 413
Database
ISI
SICI code
0021-9258(20000107)275:1<409:AAROTC>2.0.ZU;2-F
Abstract
Regulated proteolysis is important for maintaining appropriate cellular lev els of many proteins. The bulk of intracellular protein degradation is cata lyzed by the proteasome. Recently, the centrosome was identified as a novel site for concentration of the proteasome and associated regulatory protein s (Wigley, W. C., Fabunmi, R. P., Lee, M. G., Marino, C. R., Muallem, S., D eMartino, G. N., and Thomas, P. J. (1999) J. Cell Biol. 145, 481-490). Here we provide evidence that centrosomes contain the active 26 S proteasome th at degrades ubiquitinated-protein and proteasome-specific peptide substrate s. Moreover, the centrosomes contain an ubiquitin isopeptidase activity. Th e proteolytic activity is ATP dependent and is inhibited by proteasome inhi bitors, Notably, treatment of cells with inhibitors of proteasome activity promotes redistribution of the proteasome and associated regulatory protein s to the centrosome independent of an intact microtubule system. These data provide biochemical evidence for active proteasomal complexes at the centr osome, highlighting a novel function for this organizing structure.