Facilitation of proteasomal degradation of p27Kip1 by N-terminal cleavage and their sequence requirements.
The sequence requirement for N-terminal cleavage and the proteasomal degradation of p27Kip1 and their relationship was investigated. Residues 5-8 were required for the cleavage and the mutation of S10 to E inhibited the cleavage. The C-terminal PEST sequence was necessary for the degradation and residue R165 was found to play an important role in the degradation. The inhibition of the cleavage by deleting residues 5-8 inhibited the degradation, while the fragment mimicking the cleavage product accelerated the degradation. Both the cleavage and degradation demonstrated a similar sensitivity toward proteasome inhibitors and ATP depletion. These two processes are thus suggested to be tightly linked and sequential.
Hirano
Katsuya
K
Division of Molecular Cardiology, Research Institute of Angiocardiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. khirano@molcar.med.kyushu-u.ac.jp
Ihara
Eikichi
E
Hirano
Mayumi
M
Nishimura
Junji
J
Nawata
Hajime
H
Kanaide
Hideo
H
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D050760:Cyclin-Dependent Kinase Inhibitor p27; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D009097:Multienzyme Complexes / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011480:Protease Inhibitors / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013552:Swine
C436291:CDKN1B protein, human; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009097:Multienzyme Complexes; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex