Biomaterial Database

Phosphorylated nonhistone proteins in different fractions of rat liver nuclei obtained by metrizamide gradient centrifugation. 1983

G Schmidt, and A Weihe, and S Heymann, and R Lindigkeit

The distribution of nuclear nonhistone proteins (NHPs) labelled in vivo with 32P was investigated in different subnuclear fractions obtained by metrizamide gradient centrifugation of mildly sonicated rat liver nuclei. The bulk chromatin banding at 1.20-1.22 g to cm3 (fraction C) contained only minor amounts both of non-phosphorylated and 32P-labelled NHPs. Nick-translated DNA sequences were found to sediment at a slightly higher density (1.26 g/cm3) in a minor fraction (A). Fraction A also contained a significant portion of the newly synthesized RNA and was enriched additionally with a broad spectrum of NHPs; some of them were highly 32P-labelled. Two hnRNP fractions (R2 and R1) sedimenting at densities greater than 1.28 g/cm3 were analyzed, too. By SDS-PAGE it was shown that the most abundant 32P-NHPs were found in three groups (fraction A, R1, and R2). Two of them, 32-34 KDa, and 37-40 KDa, are components of the major proteins of the hnRNP particles. A group of four moderately labelled 32P-NHPs of approximately 55 K, 64 K, 70 K, and 90 KDa appeared substantially enriched in fraction A. They were found also in RNP fractions R1 and R2, but to a smaller mount. Therefore, we suggest that in fraction A they exist in a complex with hnRNP. Fraction A was also enriched with numerous 32P-NHPs of very high molecular weight found in other types of experiments nearly exclusively in the nuclear residual structures. The 32P-protein pattern of the nucleoli was shown to be different from that of the other subnuclear fractions. Considering our observations on the accumulation of nick-translated DNA sequences, the presence of newly synthesized RNA, the high content of NHPs, and the association of special 32P-NHPs we suggest that fraction A represents transcriptionally active chromatin.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008793	Metrizamide	A solute for density gradient centrifugation offering higher maximum solution density without the problems of increased viscosity. It is also used as a resorbable, non-ionic contrast medium.	Amipak,Amipaque
D009963	Orotic Acid	An intermediate product in PYRIMIDINE synthesis which plays a role in chemical conversions between DIHYDROFOLATE and TETRAHYDROFOLATE.	Potassium Orotate,Sodium Orotate,Zinc Orotate,Acid, Orotic,Orotate, Potassium,Orotate, Sodium,Orotate, Zinc
D010750	Phosphoproteins		Phosphoprotein
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
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
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002843	Chromatin	The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.	Chromatins
D002868	Chromosomal Proteins, Non-Histone	Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.	Non-Histone Chromosomal Proteins,Chromosomal Proteins, Non Histone,Chromosomal Proteins, Nonhistone,Non-Histone Chromosomal Phosphoproteins,Chromosomal Phosphoproteins, Non-Histone,Non Histone Chromosomal Phosphoproteins,Non Histone Chromosomal Proteins,Nonhistone Chromosomal Proteins,Proteins, Non-Histone Chromosomal