Biomaterial Database

Function of nucleophosmin/B23, a nucleolar acidic protein, as a histone chaperone. 2001

M Okuwaki, and K Matsumoto, and M Tsujimoto, and K Nagata

Laboratory of Cellular Biochemistry, RIKEN (The Institute of Physical and Chemical Research), Wako, Japan.

We previously identified and purified a nucleolar phosphoprotein, nucleophosmin/B23, as a stimulatory factor for replication from the adenovirus chromatin. We show here that nucleophosmin/B23 functions as a histone chaperone protein such as nucleoplasmin, TAF-I, and NAP-I. Nucleophosmin/B23 was shown to bind to histones, preferentially to histone H3, to mediate formation of nucleosome, and to decondense sperm chromatin. These activities of B23 were dependent on its acidic regions as other histone chaperones, suggesting that B23/nucleophosmin is a member of histone chaperone proteins.

UI	MeSH Term	Description	Entries
D009687	Nuclear Proteins	Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.	Nucleolar Protein,Nucleolar Proteins,Nuclear Protein,Protein, Nuclear,Protein, Nucleolar,Proteins, Nuclear,Proteins, Nucleolar
D002466	Cell Nucleolus	Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)	Plasmosome,Cell Nucleoli,Nucleoli, Cell,Nucleolus, Cell,Plasmosomes
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D006657	Histones	Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.	Histone,Histone H1,Histone H1(s),Histone H2a,Histone H2b,Histone H3,Histone H3.3,Histone H4,Histone H5,Histone H7
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000090243	Nucleophosmin	Predominantly localized in the CELL NUCLEOLUS, involved in diverse cellular processes such as ribosome biogenesis, cytoplasmic-nuclear trafficking, centrosome duplication, and regulation of p53.	NO38 Protein,Nucleolar Phosphoprotein B23,Nucleolar Protein B23,Nucleophosmid,Numatrin,Phosphoprotein B23, Nucleolus,Protein B23,B23, Nucleolar Phosphoprotein,B23, Nucleolar Protein,B23, Nucleolus Phosphoprotein,B23, Protein,Nucleolus Phosphoprotein B23,Phosphoprotein B23, Nucleolar,Protein B23, Nucleolar,Protein, NO38
D018832	Molecular Chaperones	A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.	Chaperones, Molecular,Chaperone, Molecular,Molecular Chaperone