title: CHIP mediates down-regulation of nucleobindin-1 in preosteoblast cell line models.
abstract: Nucleobindin-1 (NUCB1), also known as Calnuc, is a highly conserved, multifunctional protein widely expressed in tissues and cells. It contains two EF-hand motifs which have been shown to play a crucial role in binding Ca(2+) ions. In this study, we applied comparative two-dimensional gel electrophoresis to characterize differentially expressed proteins in HA-CHIP over-expressed and endogenous CHIP depleted MC3T3-E1 stable cell lines, identifying NUCB1 as a novel CHIP/Stub1 targeted protein. NUCB1 interacts with and is down-regulated by CHIP by both proteasomal dependent and independent pathways, suggesting that CHIP-mediated down-regulation of nucleobindin-1 might play a role in osteoblast differentiation. The chaperone protein Hsp70 was found to be important for CHIP and NUCB1 interaction as well as CHIP-mediated NUCB1 down-regulation. Our findings provide new insights into understanding the stability regulation of NUCB1.
authors.affiliation: Department of Obstetrics and Gynecology, Tai'an Central Hospital, 29 Longtan Road, Tai'an 271000, People's Republic of China.
authors.forename: Fuying
authors.initials: F
authors.lastname: Xue
authors.affiliation: Department of Brain Disease, Traditional Chinese Medical Hospital of Tai'an City, Tai'an 271000, People's Republic of China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, People's Republic of China. Electronic address: xinghui_zhao@163.com.
authors.forename: Xinghui
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, People's Republic of China.
authors.forename: Taoran
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Meng
authors.affiliation: Department of Veterinary Medicine, Beijing Institute of Animal, Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China.
authors.forename: Zhanzhong
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, People's Republic of China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Guo
authors.affiliation: Laboratory of Vaccine and Antibody Engineering, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, People's Republic of China. Electronic address: cw0226@foxmail.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D000080866:Nucleobindins; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D040901:Proteomics; D015398:Signal Transduction; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D018840:HSP70 Heat-Shock Proteins; C000630649:NUCB1 protein, human; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; C492951:Stub1 protein, mouse; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex
keywords: CHIP; Comparative two-dimensional gel electrophoresis; Heat shock proteins; Nucleobindin-1; Osteoblast differentiation