Studies of Nuclear Acidic Proteins

Changes in quantities of high-mobility-group protein 1 in oviduct cellular fractions after oestrogen stimulation

“…Thus the finding of HMG 1 in the microsomal and cytosol fractions is not surprisim'g. In eukaryotic cells, the chromosomal non-histone proteins are involved in the regulation of genomic activity (Teng et al, 1971;Kostraba & Wang, 1975). The stimulation of non-histone-protein synthesis by oestrogen treatment has previously been reported in the chromatin of rat uterine tissue and chick oviduct (Teng & Hamilton, 1969;Spelsberg et al, 1973;Teng & Teng, 1980).…”

“…The nuclear Percentage of complement fixed = pellet was further purified by suspension in 2.2Msucrose and centrifuged at 105 OOOg for 1 h. The supernatant of the 27 0OOg-centrifugation step, containing mitochondria and microsomal fraction, was further centrifuged for 15min at 56000g to remove mitochondria. The resulting supernatant was centrifuged at 105 000g for 30min to obtain the microsomal fraction in the pellet and cytosol fraction in the supernatant (Teng et al, 1971). The nuclear, microsomal and cytosol HMG 1 protein was extracted with 5% (w/v) HCl04 and precipitated with 6 vol.…”

Presence of multiple protein kinase activities in rat liver nuclei

“…The phosphorylation of nuclear proteins has been suggested to play a role in the control of gene readout in mammalian tissues (1,2,3). Phosphorylation of histones has been shown to occur in rat liver in response to hormonal agents (4), and a histone phosphokinase has been isolated from calf liver (5).…”

Studies in vitro of the effects of adenosine 3′:5′-cyclic monophosphate on the phosphorylation of nuclear proteins in isolated rat heart nuclei

“…Early increases in the synthesis of non-histone proteins have been reported before induced synthesis of DNA in WI-38 human fibroblasts (Tsuboi & Baserga, 1972), lymphocytes (Levy et al, 1973), synchronized HeLa cells (Stein & Baserga, 1970) and salivary glands after administration of isoproterenol (Kleinsmith & Allfrey, 1969). These proteins are extensively phosphorylated (Ahmad & Ishida, 1971;Shea & Kleinsmith, 1973;Johnson et al, 1974), and the extent of phosphorylation appears to determine their ability to interact with DNA (Wang, 1967;Teng et al, 1971;Kleinsmith, 1973). It has been reported that phosphorylation of non-histone proteins might be associated with the increased rate of RNA synthesis (Kamiyama et al, 1972;Platz et al, 1973;Karn et al, 1974), and suggestions have been made that the former might be one of the mechanisms by which gene expression is controlled at the level of RNA transcription (Stein & Baserga, 1972;Shea &Kleinsmith, 1973;Vidali etal., 1973;Garrard et al, 1974;MacGillivray & Rickwood, 1974).…”