[HTML][HTML] Down-regulation of p27 Kip1 by two mechanisms, ubiquitin-mediated degradation and proteolytic processing
M Shirane, Y Harumiya, N Ishida, A Hirai… - Journal of Biological …, 1999 - ASBMB
The intracellular level of p27 Kip1, a cyclin-dependent kinase (CDK) inhibitory protein, is
rapidly reduced at the G 1/S transition phase when the cell cycle pause ceases. In this study,
we demonstrated that two posttranslational mechanisms were involved in p27 Kip1
breakdown: degradation via the ubiquitin (Ub)-proteasome pathway and proteolytic
processing that rapidly eliminates the cyclin-binding domain. We confirmed that p27 Kip1
was ubiquitinated in vitroas well as in vivo. The p27 Kip1-ubiquitination activity was higher at …
rapidly reduced at the G 1/S transition phase when the cell cycle pause ceases. In this study,
we demonstrated that two posttranslational mechanisms were involved in p27 Kip1
breakdown: degradation via the ubiquitin (Ub)-proteasome pathway and proteolytic
processing that rapidly eliminates the cyclin-binding domain. We confirmed that p27 Kip1
was ubiquitinated in vitroas well as in vivo. The p27 Kip1-ubiquitination activity was higher at …