Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The catalytic (alpha) subunit of casein kinase II from Drosophila, cloned and expressed in Escherichia coli (Saxena, A., Padmanabha, R., and Glover, C. V. C., (1987) Mol. Cell. Biol. 7, 3409-3417), has been purified and characterized, and the properties have been compared to those of the holoenzyme. The catalytic subunit exhibits protein kinase activity with casein as substrate and is autophosphorylated. The specific activity of the purified subunit is 6% of the activity of the holoenzyme from reticulocytes or from Drosophila. The alpha subunit is a monomer, eluting at Mr = 40,000 upon gel filtration in high salt, but as part of an aggregate in low salt. The alpha subunit has been purified to apparent homogeneity by sequential chromatography on DEAE-cellulose, Mono S, and Mono Q. A single band, Mr = 37,000, is detected by silver staining following polyacrylamide gel electrophoresis. The isolated alpha subunit displays apparent Km values for beta casein, ATP, and GTP similar to those of the holoenzyme. The activity of the alpha subunit is inhibited by heparin with an I50 of 0.1-0.3 micrograms/ml, a value similar to that observed for the holoenzyme; autophosphorylation is also inhibited by heparin. Polylysine has no stimulatory effect on the activity of the catalytic subunit, as measured with casein and by autophosphorylation, but stimulates both activities with the holoenzyme. When physiological substrates for casein kinase II are examined, glycogen synthase and eukaryotic initiation factor 3 (eIF-3) (p120) are phosphorylated by the alpha subunit at a rate equivalent to that of the holoenzyme, while phosphorylation of eIF-3 (p67) is reduced 9-fold and eIF-2 beta is not modified. From these data, it can be concluded that the alpha subunit of casein kinase II is sufficient for catalysis, is autophosphorylated, and can be directly inhibited by heparin, whereas the beta subunit mediates the effects of basic stimulatory compounds and is involved in recognition and/or binding to specific physiological substrates.
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PMID:Characterization of the catalytic subunit of casein kinase II expressed in Escherichia coli and regulation of activity. 190 Aug 38

The relationship between terminal cell differentiation and changes in the subcellular levels of the HER-2/neu antigen was investigated in cultured human breast cancer cells: AU-565 cells (which overexpress the HER-2/neu gene) and MCF-7 cells (which do not overexpress this gene). Differentiation was achieved by treating the cells with mycophenolic acid (MPA), phorbol 12-myristate 13-acetate (PMA), retinoic acid (RA), or the TA-1 monoclonal antibody to the extracellular domain of the HER-2/neu protein. Ten to twenty percent of the cells in untreated, sparsely growing AU-565 cultures exhibited morphological maturation characterized by large lacy nuclei surrounded by sizable flat cytoplasms. A fraction of these cells harbored milk factors such as casein and large lipid droplets. Treatment of the AU-565 cells for 4 d with 9 microM MPA, 1.6 nM PMA, 2.5 microM RA, or 1 microgram/mL TA-1 antibody resulted in cell growth inhibition and an increase in the percentage of cells (48-97%) that exhibit a mature phenotype. MCF-7 cells were also susceptible to differentiation by MPA and RA, but to a lesser degree than the AU-565 cells. Differentiation in the AU-565 and MCF-7 cells was associated with reduced immunostaining for the HER-2/neu protein at the cell surface membrane and with a transient increased diffuse immunostaining for this protein in the cytoplasm.
Mol Carcinog 1990
PMID:Differentiation of cultured human breast cancer cells (AU-565 and MCF-7) associated with loss of cell surface HER-2/neu antigen. 198 May 88

Casein kinase II (CKII) phosphorylates the mammalian transcription factor serum response factor (SRF) on a serine residue(s) located within a region of the protein spanning amino acids 70 to 92, thereby enhancing its DNA-binding activity in vitro. We report here that serine 83 appears to be the residue phosphorylated by CKII but that three other serines in this region can also be involved in phosphorylation and the enhancement of DNA-binding activity. A mutant that contained glutamate residues in place of these serines had only low-level binding activity; however, when the serines were replaced with glutamates and further mutations were made that increased the negative charge of the region, the resulting mutant showed a constitutively high level of binding equal to that achieved by phosphorylation of wild-type SRF. We have investigated the mechanism by which phosphorylation of SRF increases its DNA-binding activity. We have ruled out the possibilities that phosphorylation affects SRF dimerization or relieves inhibition due to masking of the DNA-binding domain by an amino-terminal region of the protein. Rather, using partial proteolysis to probe SRF's structure, we find that the conformation of SRF's DNA-binding domain is altered by phosphorylation.
Mol Cell Biol 1991 Jul
PMID:Mutation of serum response factor phosphorylation sites and the mechanism by which its DNA-binding activity is increased by casein kinase II. 204 71

Transcription from the beta-casein milk protein gene promoter is induced by the synergistic action of glucocorticoid and prolactin hormones in the murine mammary epithelial cell line, HC11. We analyzed the binding of nuclear proteins to the promoter and determined their binding sites. Site-directed mutagenesis was used to determine the function of nuclear factor binding. During lactogenic hormone induction of HC11 cells, the binding of two nuclear factors increased. The binding of two other nuclear factors, present in uninduced cells, decreased. The basal activity of the promoter could be increased to and above the level of the induced wild-type promoter when the recognition sequences of the negatively regulated factors were mutated. This suggests that the beta-casein promoter is regulated by the relief of the repression of transcription. An essential tissue-specific factor was also found in nuclear extracts from the mammary glands of mice. Mutation of its recognition sequence in the beta-casein promoter led to the abolition of the induction of transcription by lactogenic hormones. The DNA sequences recognized by all five of these nuclear factors are conserved in the promoters of different casein genes from several species, confirming their importance in the regulation of milk protein gene transcription.
Mol Cell Biol 1991 Jul
PMID:Beta-casein gene promoter activity is regulated by the hormone-mediated relief of transcriptional repression and a mammary-gland-specific nuclear factor. 204 76

Intra-alveolar fibrin deposition accompanies many forms of inflammatory lung injury. Appropriate clearance of this fibrin matrix is important for normal healing and remodeling. The local generation of plasmin by the action of plasminogen activators (PAs) represents a pivotal step in the fibrinolytic process. To investigate whether the alveolar epithelium plays a role in the modulation of intra-alveolar fibrinolysis, we have studied PA regulation by rat pulmonary alveolar epithelial cells. We have found large quantities of PA activity both in conditioned media and cell lysates from epithelial monolayers in culture. Casein-plasminogen zymography reveals that this PA activity migrates as a tight doublet with an apparent mol wt of 45 kD, clearly distinct from rat tissue-type PA (tPA, greater than 68 kD). Analysis of freshly isolated type II alveolar epithelial cells demonstrates readily measurable PA activity in cell lysates, as well as expression of urokinase-type PA (uPA) mRNA on Northern blot analysis. Upregulation of PA activity occurs progressively with time in culture as the alveolar epithelial cells lose type II cell characteristics and become more flattened. Stimulation of alveolar epithelial cell monolayers with lipopolysaccharide or tumor necrosis factor increases levels of secreted PA activity. The relative abundance of uPA mRNA was shown to change in parallel with PA activity during in vitro differentiation or after exposure to inflammatory mediators. Thus, alveolar epithelial cells are likely an important source of uPA in the lung, the expression of which is influenced by the state of cellular differentiation as well as the presence of inflammatory mediators.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1990 Nov
PMID:Expression of urokinase-type plasminogen activator by rat pulmonary alveolar epithelial cells. 212 Nov 71

It is well known that cultured Sertoli cells secrete plasminogen activators (Lacroix et al., Mol Cell Endocrinol 1977; 9:227-236; Hettle et al., Biol Reprod 1986; 34:895-904). We now show that testicular cells in culture also secrete gelatinolytic metalloproteinases. Gelatin zymographic analysis of concentrated culture medium proteins reveals that Sertoli cells secrete gelatinases of 185 kDa, 110 kDa, 83 kDa, 76 kDa, and 72 kDa in addition to plasminogen activators (PAs). Gelatinase 185 kDa is induced by FSH. Media from Sertoli (epithelial)/peritubular (mesenchymal) cell cocultures contain the Sertoli cell gelatinases and one FSH-stimulated gelatinase of 50 kDa, indicating that gelatinase 50 kDa is regulated by both FSH and cell-cell interactions. A 50-kDa fibronectinolytic activity is also present in the coculture medium from cells grown in the presence of FSH. Casein zymography demonstrates a prominent 30-kDa protease only in media from cocultures. Peritubular cells secrete urokinase-type plasminogen activator (u-PA) and exhibit slight degrading activity at 86 kDa and 74 kDa. The gelatinases are most active in the pH range 7.3-8.5 and are completely or partially inhibited by metal ion chelators indicating that they are metalloproteinases. Our data demonstrate that testicular cells in culture secrete several gelatinases in addition to PAs, and that FSH and coculture conditions regulate some of these secreted proteases. We suggest that the highly regulated secretion of these proteases may well be of physiological importance during testicular development and spermatogenesis.
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PMID:Secreted metalloproteinases in testicular cell culture. 212 32

The ABA-induced MA12 cDNA from maize, which encodes a set of highly phosphorylated embryo proteins, was used to isolate the corresponding genomic clone. This gene, called RAB-17 (responsive to ABA), encodes a basic, glycine-rich protein (mol. wt. 17,164) containing a cluster of 8 serine residues, seven of them contiguous. It is a homologue of the rice RAB-21 gene (Mundy J, Chua NH, EMBO J 7; 2279-2286, 1988). Phosphoamino acid analysis of the isolated protein indicates that only the serine residues are phosphorylated and a putative casein-type kinase phosphorylatable sequence was identified in the protein. The pattern of expression and in vivo phosphorylation of the RAB-17 protein was studied during maize embryo germination and in calli of both meristematic or embryonic origin. ABA treatment induced the synthesis of RAB-17 mRNA and protein in calli, however, the RAB-17 proteins were found to be highly phosphorylated only in embryos.
Plant Mol Biol 1990 Mar
PMID:Gene sequence, developmental expression, and protein phosphorylation of RAB-17 in maize. 215 15

MDG is a very important component of the Drosophila genome. MDG have many sites of localisation in chromosomes and can change their localisation. Perhaps the process of MDG integration has some specificity. To study this problem we sequenced the flanking region of MDG1 DNA. The analysis of this sequences reveals the following features. 1. The 5'-flanking sequences contain 7 TATA-boxex, 5 of which form a cluster. 2. The 3'-flanking sequences contain TTTAAA block which is similar to TATA-box for alpha- and gamma-casein genes of mammals. 3. The flanking region are rich in repeated sequences, the longest of which TCCTCCT (R) and TTCTTC (R2) are on the 5'-flank and on the 3'-flank respectively, so that the whole structure is: 5'-R1NNR1-MDG1-R2NNR2-3', where N is some nucleotide. 5'-flanking sequences are AT-rich, while the 3'-flank contains 10 consecutive thymidines 4 nucleotides apart from MDG1. The MDG1 and MDG "17.6" share several common repeats in the flanking sequences, the longest of which TACTTACAT is 63 bases upstream MDG1 and 11 bases upstream MDG "17.6". This sequence differs strongly from the consensus enhancer sequence.
Mol Biol (Mosk)
PMID:[Analysis of the primary structure of DNA sequences flanking MDG1]. 216 91

Non-histone chromatin protein (NHCP) fractions were extracted from purified beef thyroid nuclear preparations and tested for the presence of protein kinase activities using several known mediators of thyroid regulation, as well as potential phosphotransferase substrates using purified or partially purified protein kinase activities. The addition of cAMP/3-isobutyl-1-methylxanthine had no effect on NHCP histone kinase activity; the addition of 10 micrograms of the heat-stable cAMP-dependent protein kinase A inhibitor, however, resulted in a 47% reduction in histone H1 kinase activity. Nuclear casein kinase II activity was present in the NHCP fractions as evidenced by the capacity of spermine to stimulate (ED50 = 0.19 mM) and heparin to inhibit (ID50 = 0.09 microgram/ml) the phosphorylation of casein; further, the phosphotransferase activity could be purified by sequential casein-agarose and spermine-agarose affinity chromatography. Neither calcium-calmodulin nor calcium/phosphatidylserine/diolein had an effect on NHCP casein kinase or histone kinase activities, respectively. The addition of cAMP-dependent protein kinase A catalytic subunit, nuclear casein kinase II, calcium-activated calmodulin-dependent protein kinase and diacylglycerol-activated calcium/phospholipid-dependent protein kinase C activities exhibited distinct phosphorylation patterns when NHCP were used as substrates and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. We conclude that NHCP fraction from beef thyroid: 1) contains both cAMP-dependent protein kinase A catalytic subunit and nuclear casein kinase II and 2) substrates for cAMP-dependent protein kinase A, calcium-activated calmodulin-dependent protein kinase, protein kinase C, and nuclear casein kinase II.
Mol Cell Biochem 1990 Jun 25
PMID:Non-histone chromatin proteins in beef thyroid: distinct phosphorylation patterns of several protein kinases. 216 41

Casein kinase II is a widely distributed protein serine/threonine kinase. The holoenzyme appears to be a tetramer, containing two alpha or alpha' subunits (or one of each) and two beta subunits. Complementary DNA clones encoding the subunits of casein kinase II were isolated from a human T-cell lambda gt10 library using cDNA clones isolated from Drosophila melanogaster [Saxena et al. (1987) Mol. Cell. Biol. 7, 3409-3417]. One of the human cDNA clones (hT4.1) was 2.2 kb long, including a coding region of 1176 bp preceded by 156 bp (5' untranslated region) and followed by 871 bp (3' untranslated region). The hT4.1 clone was nearly identical in size and sequence with a cDNA clone from HepG2 human hepatoma cultured cells [Meisner et al. (1989) Biochemistry 28, 4072-4076]. Another of the human T-cell cDNA clones (hT9.1) was 1.8 kb long, containing a coding region of 1053 bp preceded by 171 bp (5' untranslated region) and followed by 550 bp (3' untranslated region). Amino acid sequences deduced from these two cDNA clones were about 85% identical. Most of the difference between the two encoded polypeptides was in the carboxy-terminal region, but heterogeneity was distributed throughout the molecules. Partial amino acid sequence was determined in a mixture of alpha and alpha' subunits from bovine lung casein kinase II. The bovine sequences aligned with the 2 human cDNA-encoded polypeptides with only 2 discrepancies out of 535 amino acid positions. This confirmed that the two human T-cell cDNA clones encoded the alpha and alpha' subunits of casein kinase II. Microsequence data determined from separated preparations of bovine casein kinase II alpha subunit and alpha' subunit [Litchfield et al. (1990) J. Biol. Chem. 265, 7638-7644] confirmed that hT4.1 encoded the alpha subunit and hT9.1 encoded the alpha' subunit. These studies show that there are two distinct catalytic subunits for casein kinase II (alpha and alpha') and that the sequence of these subunits is largely conserved between the bovine and the human.
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PMID:Isolation and characterization of human cDNA clones encoding the alpha and the alpha' subunits of casein kinase II. 217


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