title: Multifaceted interactions and regulation between antizyme and its interacting proteins cyclin D1, ornithine decarboxylase and antizyme inhibitor.
abstract: Ornithine decarboxylase (ODC), cyclin D1 (CCND1) and antizyme inhibitor (AZI) promote cell growth. ODC and CCND1 can be degraded through antizyme (AZ)-mediated 26S proteasomal degradation. This paper describes a mechanistic study of the molecular interactions between AZ and its interacting proteins. The dissociation constant (Kd) of the binary AZ-CCND1 complex and the respective binding sites of AZ and CCND1 were determined. Our data indicate that CCND1 has a 4-fold lower binding affinity for AZ than does ODC and an approximately 40-fold lower binding affinity for AZ than does AZI. The Kd values of AZ-CCND1, AZ-ODC and AZ-AZI were 0.81, 0.21 and 0.02 μM, respectively. Furthermore, the Kd values for CCND1 binding to the AZ N-terminal peptide (AZ34-124) and AZ C-terminal peptide (AZ100-228) were 0.92 and 8.97 μM, respectively, indicating that the binding site of CCND1 may reside at the N-terminus of AZ, rather than the C-terminus. Our data also show that the ODC-AZ-CCND1 ternary complex may exist in equilibrium. The Kd values of the [AZ-CCND1]-ODC and [AZ-ODC]-CCND1 complexes were 1.26 and 4.93 μM, respectively. This is the first paper to report the reciprocal regulation of CCND1 and ODC through AZ-dependent 26S proteasomal degradation.
authors.affiliation: Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan.
authors.forename: Yen-Chin
authors.initials: YC
authors.lastname: Liu
authors.affiliation: Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan.|Graduate Institute of Biotechnology, National Chung-Hsing University (NCHU), Taichung, Taiwan.|Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.
authors.forename: Chien-Yun
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Chi-Li
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Biotechnology Center, National Chung-Hsing University (NCHU), Taichung, Taiwan.|Agricultural Biotechnology Center (ABC), National Chung-Hsing University (NCHU), Taichung, Taiwan.
authors.forename: Hui-Yi
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Institute of Microbiology & Immunology, Chung Shan Medical University, Taichung, Taiwan.|Division of Allergy, Immunology, and Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Guang-Yaw
authors.initials: GY
authors.lastname: Liu
authors.affiliation: Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan.|Agricultural Biotechnology Center (ABC), National Chung-Hsing University (NCHU), Taichung, Taiwan.|Institute of Genomics and Bioinformatics, National Chung Hsing University (NCHU), Taichung, Taiwan.
authors.forename: Hui-Chih
authors.initials: HC
authors.lastname: Hung
mesh_terms: D001665:Binding Sites; D019938:Cyclin D1 / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009857:Oncogenes; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D065108:Ornithine Decarboxylase Inhibitors / Q000737:chemistry; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000037:antagonists & inhibitors*; D011994:Recombinant Proteins / Q000378:metabolism; D012156:Reticulocytes / Q000166:cytology; D015398:Signal Transduction
chemical_list: C530104:CCND1 protein, human; D065108:Ornithine Decarboxylase Inhibitors; D011506:Proteins; D011994:Recombinant Proteins; C031017:ornithine decarboxylase antizyme; D019938:Cyclin D1; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D009955:Ornithine Decarboxylase
keywords: biochemistry; cell cycle; molecular and cellular biology; oncogene; signal transduction