Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genes actively involved in the G0/G1 switch (G0S genes) may be differentially expressed during the lectin-induced switch of lymphocytes from the G0 to the G1 phases of the cell cycle. This paper presents studies of G0S2, a member of a set of putative G0S genes, for which cDNAs were cloned and selected on the basis of differential cDNA hybridization. G0S2 mRNA increases transiently within 1-2 hr of the addition of lectin or cycloheximide to cultured blood mononuclear cells. Comparison of a nearly full-length cDNA sequence with the corresponding genomic sequence reveals one small intron and an open reading frame in the second exon. The derived 103-amino-acid basic protein has two potential alpha-helical domains separated by a hydrophobic region with the potential to generate turns and assume a beta-sheet conformation. Consistent with involvement in the G0/G1 switch, the protein contains potential sites for phosphorylation by protein kinase C and casein kinase II. The gene contains a CpG-rich island suggesting expression in the germ line. An upstream segment contains tandem dinucleotide repeats (CT)19/(CA)16. There is a suitably located TATA box, but potential sites for CCAAT-box binding factors are far upstream, embedded in a 42-nucleotide repeat element. Potential sites for transcription factors AP1, AP2, and AP3 are consistent with rapid transcriptional activation in response to inducing agents.
 ...
PMID:A human putative lymphocyte G0/G1 switch gene containing a CpG-rich island encodes a small basic protein with the potential to be phosphorylated. 193 Jun 93

The cDNA for the human alpha-adducin gene has been cloned, and different alternately spliced forms have been identified. We report the complete genomic organization of the human alpha-adducin gene and these alternately spliced forms. The human alpha-adducin gene, spanning approximately 85 kb, consists of 16 exons ranging in size from 34 to 1892 bp. One of the spliced forms of the human alpha-adducin gene results from alternate use of the 5' splice donor site for exon 10, while another results in a truncated protein following insertion of 34 bp comprising exon 15, followed by a premature stop codon. This alternate spliced form of alpha-adducin is predicted to result in an altered carboxyl terminus that would eliminate a protein kinase and calmodulin binding site. Seven nucleotide substitutions and 4 insertion/deletions were also identified. The 5' region of the human alpha-adducin gene contains one Sp1 site, two AP2 sites, and two CAAT boxes. No TATA box was apparent, consistent with features of a housekeeping gene. We have mapped another cDNA within the first intron of the human alpha-adducin gene, suggesting overlapping genes in this 4p16.3 genomic region.
 ...
PMID:Genomic organization of the human alpha-adducin gene and its alternately spliced isoforms. 777 61

The Plk gene encodes a serine/threonine protein kinase believed to be important for the normal progression of mammalian cells through the cell cycle. In this paper, we report the genomic organization of the mouse Plk gene. The mouse Plk gene encompasses 16 kb of the mouse genome and is organised into 10 exons. Based on homology with the human PLK1 promoter region, the putative mouse promoter region includes a CCAAT motif but lacks the conventional TATA motif. The proposed promoter region contains consensus binding sites for several transcriptional regulators, including Sp1 and AP2. In addition to the active copy of Plk, Plk exists as a processed pseudogene. Using RFLP analysis, we have localized the active Plk gene to mouse Chromosome 7 and the processed pseudogene to mouse Chromosome 5. Southern blot analysis of DNA from a limited number of other mammalian species suggests that the duplication is confined to the mouse. Parsimony analysis suggests that the gene duplication leading to the mouse Plk pseudogene occurred after the rat-mouse split.
 ...
PMID:The mouse Plk gene: structural characterization, chromosomal localization and identification of a processed Plk pseudogene. 937 Feb 99

ChAT (choline acetyltransferase) is the enzyme responsible for acetylcholine synthesis and is specifically expressed in cholinergic neurons. To further characterize the transcriptional regulation of the hCHAT (human ChAT) gene by NGF, we examined the effects upon ChAT promoter activity of a family of transcription factors which are activated by NGF and several extracellular stimuli and encoded by immediate-early genes. These include NGFI-A (Egr1, zif268), NGFI-C (Egr2), Krox-20 and NGFI-B (Nurr77). Two fragments of the hChAT gene were used for functional analysis carrying 944 bp (P1) and 4000 bp (P1 + P2) of the 5' flanking region in front of the chloramphenicol acetyltransferase (CAT) reporter gene. They were transiently co-transfected with NGFI-A, NGFI-C, Krox-20 and NGFI-B expression vectors in NG108-15, SN6 and COS-1 cells. CAT activity after transfection of the p4000 ChAT-CAT reporter into both neuronal cell lines (NG108-15 and SN6 cells) was increased up to 5-fold in the presence of co-transfected NGFI-A and up to 5- and 12-fold after co-transfection of NGFI-C expression vector in NG108-15 and SN6 cells, respectively. In NG108-15 cells, dbcAMP excerted a strong enhancing activity on the transactivation properties of NGFI-C while this was not observed when cells were transfected with NGFI-A. These trans-activation effects were specific for neuronal cells. When NG108-15 cells were treated with dbcAMP in the presence of H89, a specific PKA inhibitor, the increase of transcriptional activity of NGFI-C was abolished, indicating that a signalling transduction mechanism through PKA plays a role in NGFI-C-induced trans-activation. Electrophoretic mobility-shift assays showed that the sequence GCCCGGGGAG (NGFRE) located 1205 bp upstream of the first coding ATG (E1) can bind NGFI-A but not NGFI-C. Several possibilities explaining the observed results are discussed. Finally, transfections of ChAT-CAT reporters including the P1 + P2 region or a minimal ChAT enhancer present in the P2 region in front of a heterologous promoter indicated the presence of a regulatory element which conferred AP2-dependent trans-activation with homologous as well as with heterologous promoter constructs.
 ...
PMID:Transcriptional activation of human choline acetyltransferase by AP2- and NGF-induced factors. 938 76

The mechanisms responsible for coated pit formation in cells remain unknown, but indirect evidence has argued both for and against a critical role of receptor cytoplasmic domains in the process. If the endocytic motifs of receptors are responsible for recruiting AP2 to the plasma membrane, thereby driving coated pit formation, then the level of constitutively internalized receptors at the membrane would be expected to govern the steady-state level of coated pits in cells. Here we directly test this hypothesis for broad classes of receptors containing three distinct constitutive internalization signals. Chimeric proteins consisting of an integral membrane reporter protein (Tac) coupled to cytoplasmic domains bearing tyrosine-, di-leucine-, or acidic cluster/casein kinase II-based internalization signals were overexpressed to levels that saturated the internalization pathway. Quantitative confocal immunofluorescence microscopy indicated that the number of plasma membrane clathrin-coated pits and the concentration of their structural components were invariant when comparing cells expressing saturating levels of the chimeric receptors to nonexpressing cells or to cells expressing only the Tac reporter lacking cytoplasmic internalization signals. Biochemical analysis showed that the distribution of coat proteins between assembled coated pits and soluble pools was also not altered by receptor overexpression. Finally, the cellular localizations of AP2 and AP1 were similarly unaffected. These results provide a clear indication that receptor endocytic signals do not determine coated pit levels by directly recruiting AP2 molecules. Rather, the findings support a model in which coated pit formation proceeds through recruitment and activation of AP2, likely through a limited number of regulated docking sites that act independently of endocytic signals.
 ...
PMID:Endocytic clathrin-coated pit formation is independent of receptor internalization signal levels. 957 Dec 48

Activation of D1-like dopamine (DA) receptors reduces peak Na(+) current in acutely isolated hippocampal neurons via a modulatory mechanism involving phosphorylation of the Na(+) channel alpha subunit by cAMP-dependent protein kinase (PKA). Peak Na(+) current is reduced 20-50% in the presence of the D1 agonist SKF 81297 or the PKA activator Sp-5,6-dichloro-l-beta-d-ribofuranosyl benzimidazole-3',5'-cyclic monophosphorothionate (cBIMPS). Co-immunoprecipitation experiments show that Na(+) channels are associated with PKA and A-kinase-anchoring protein 15 (AKAP-15), and immunocytochemical labeling reveals their co-localization in the cell bodies and proximal dendrites of hippocampal pyramidal neurons. Anchoring of PKA near the channel by an AKAP, which binds the RII alpha regulatory subunit, is necessary for Na(+) channel modulation in acutely dissociated hippocampal pyramidal neurons. Intracellular dialysis with the anchoring inhibitor peptides Ht31 from a human thyroid AKAP and AP2 from AKAP-15 eliminated the modulation of the Na(+) channel by the D1-agonist SKF 81297 and the PKA activator cBIMPS. In contrast, dialysis with the inactive proline-substituted control peptides Ht31-P and AP2-P had little effect on the D1 and PKA modulation. Therefore, we conclude that modulation of the Na(+) channel by activation of D1-like DA receptors requires targeted localization of PKA near the channel to achieve phosphorylation of the alpha subunit and to modify the functional properties of the channel.
 ...
PMID:Dopaminergic modulation of voltage-gated Na+ current in rat hippocampal neurons requires anchoring of cAMP-dependent protein kinase. 1046 Feb 75

Dopamine (DA) is a key hormone in mammalian sodium homeostasis. DA induces natriuresis via acute inhibition of the renal proximal tubule apical membrane Na(+)/H(+) exchanger NHE3. We examined the mechanism by which DA inhibits NHE3 in a renal cell line. DA acutely decreases surface NHE3 antigen in dose- and time-dependent fashion without altering total cellular NHE3. Although DA(1) receptor agonist alone decreases surface NHE3, simultaneous DA(2) agonist synergistically enhances the effect of DA(1). Decreased surface NHE3 antigen, caused by stimulation of NHE3 endocytosis, is dependent on intact functioning of the GTPase dynamin and involves increased binding of NHE3 to the adaptor protein AP2. DA-stimulated NHE3 endocytosis can be blocked by pharmacologic or genetic protein kinase A inhibition or by mutation of two protein kinase A target serines (Ser-560 and Ser-613) on NHE3. We conclude that one mechanism by which DA induces natriuresis is via protein kinase A-mediated phosphorylation of proximal tubule NHE3 leading to endocytosis of NHE3 via clathrin-coated vesicles.
 ...
PMID:Dopamine acutely stimulates Na+/H+ exchanger (NHE3) endocytosis via clathrin-coated vesicles: dependence on protein kinase A-mediated NHE3 phosphorylation. 1132 6

Epidemiological and preclinical studies demonstrate that consumption of diets high in omega-3 fatty acids (n-3 PUFAs) reduce the risk of colon cancer. Docosahexaenoic acid (DHA), a long chain polyunsaturated fatty acid (PUFAs) is a major constituent of nutrients rich in n-3 PUFAs. There are studies to indicate that colon tumor inhibition by n-3 PUFA-rich diets is, in part, mediated through modulation of signaling pathways that alter gene expression which are involved in colon tumor growth. In the present study using CaCo-2 colon cancer cell lines we examined the effects of DHA on the genetic precursors of human colon cancer at the transcription level using DNA oligonucleotide arrays. Our results indicated that DHA inhibits the growth of CaCo-2 cells and induces apoptosis. For gene expression analysis using DNA microarrays, total RNA extracted from DHA treated CaCo-2 cells was converted to cDNA, labeled with Cy5-dCTP (DHA-treated) and Cy3-dCTP (untreated cells) and used as probes for hybridization in human chip spotted with 3,800 oligonucleotides consisting of 156 functional categories. The expression profiles of genes indicated a reprogramming pattern of previously known and unknown genes and transcription factors that provided clues to the possible functional mechanism of DHA. An average of (ratios from triplicate experiments) 504 out of 3,800 genes expressed after 48 h of DHA treatment. Altered expression on the transcription factors includes down regulation of nine members of the RNA II polymerases, transcription co-repressor associated protein and enhancer binding proteins such as AP2, in addition to changes in the expression of zinc finger group of transcription factors. Activation of cytochrome c which triggers caspases was associated with the elevated expression of pro-apoptotic caspases 10, 13, 8, 5 and 9 in DHA treated cells. Activation of cyclin-dependent kinase inhibitors such as p21 (waf1/cip1), p27, p57, p19 and growth arrest specific proteins by more than 2-fold is consistent with the induction of apoptosis and inactivation of antiapototic Bcl-2 family of genes. Inactivation of prostaglandin family of genes, lipoxygenases and altered expression of peroxisome proliferators (PPARalpha and gamma) by DHA seem to indicate a lipid peroxidation-induced apoptosis in addition to effect reflected on the modification of cell cycle regulatory genes. These findings support the conclusion that a genomewide expression profiling of human colon cancer precursor genes and transcription factors provides a set of novel regulatory mechanism(s) to determine the chemopreventive efficacy of DHA and thus to prevent the inflammation and neoplasia.
 ...
PMID:Docosahexaenoic acid regulated genes and transcription factors inducing apoptosis in human colon cancer cells. 1171 97

Aquaporin 4 (AQP4) is the predominant water channel in the brain. It is targeted to specific membrane domains of astrocytes and plays a crucial role in cerebral water balance in response to brain edema formation. AQP4 is also specifically expressed in the basolateral membranes of epithelial cells. However, the molecular mechanisms involved in its polarized targeting and membrane trafficking remain largely unknown. Here, we show that two independent C-terminal signals determine AQP4 basolateral membrane targeting in epithelial MDCK cells. One signal involves a tyrosine-based motif; the other is encoded by a di-leucine-like motif. We found that the tyrosine-based basolateral sorting signal also determines AQP4 clathrin-dependent endocytosis through direct interaction with the mu subunit of AP2 adaptor complex. Once endocytosed, a regulated switch in mu subunit interaction changes AP2 adaptor association to AP3. We found that the stress-induced kinase casein kinase (CK)II phosphorylates the Ser276 immediately preceding the tyrosine motif, increasing AQP4-mu 3A interaction and enhancing AQP4-lysosomal targeting and degradation. AQP4 phosphorylation by CKII may thus provide a mechanism that regulates AQP4 cell surface expression.
 ...
PMID:Polarized trafficking and surface expression of the AQP4 water channel are coordinated by serial and regulated interactions with different clathrin-adaptor complexes. 1174 78

Several peripheral membrane proteins associated with clathrin-coated vesicles (CCVs) are reversibly phosphorylated, but it is not clear precisely which protein kinases are involved. In order to address this question directly, we have isolated highly purified CCVs from porcine brain. The peripheral membrane proteins have been removed and assayed for kinase activity using the CCV peripheral membrane proteins as substrate. The major kinase activity identified has a molecular mass of 40 kDa, is inhibited by known specific inhibitors of the protein kinase CK2 and is recognised by an antibody specific to CK2. We show that CK2 is responsible for the phosphorylation of the majority of CCV-associated proteins that are subject to phosphorylation. Intriguingly, CK2 is inactive when associated with CCVs but becomes active once the clathrin coat has been removed. The medium subunit of the AP2 adaptor complex (mu2) is not a substrate for CK2, but is phosphorylated by a second kinase that we show to be cyclin G-associated kinase (GAK/auxilin2). Unlike the situation for the CK2 substrates, mu2 is a substrate for GAK/auxilin2, both in intact CCVs and in solution. In addition, we show that the 'stripped' CCV membranes that remain once the peripheral membrane proteins have been removed from CCVs inhibit CK2 but not GAK/auxilin2 activity.
 ...
PMID:CK2 and GAK/auxilin2 are major protein kinases in clathrin-coated vesicles. 1201 Apr 61


1 2 3 4 5 Next >>