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)

1. The phosphorylation of troponin T from rabbit white sketetal muscle is catalysed by phosphorylase kinase, but not at a significant rate by bovine 3':5'-cyclic AMP-dependent protein kinase. 2. The amino acid sequences adjacent to the three major phosphorylation sites of troponin T were determined. 3. The serine in the N-terminal peptide (Asx,SerP, Glx)Glu-Val-Glu, is that phosphorylated (SerP, phosphoserine) when the troponin complex is isolated. 4. The other two sites of phosphorylation are located in the sequence Ala-Leu-(Ser, SerP)-Met-Gly-Ala-Asn-Tyr(Ser,SerP)Tyr. 5. When troponin T is phosphorylated in the presence of troponin C, the extent of phosphorylation at each site is considerably decreased. 6. CNBr fragments of troponin T are also phosphorylated by phosphorylase kinase, but the rate of phosphorylation at each site in the CNBr fragments is considerably slower than in the native protein. 7. From these studies it is suggested that troponin C interacts with troponin T in the region containing the two closely situated phosphorylation sites.
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PMID:The phosphorylation sites of troponin T from white skeletal muscle and the effects of interaction with troponin C on their phosphorylation by phosphorylase kinase. 84 66

The mechanism by which thrombin induces neurite retraction was studied in NB2a mouse neuroblastoma cells. The rapid effect of thrombin (completed within minutes) appears to involve an interaction between its anion-binding exosite and the thrombin receptor. Structural alterations of this site increase the EC50 for thrombin-mediated retraction, and a hirudin C-terminal peptide that blocks this site inhibits the response. The thrombin effect was mimicked by a 14 amino acid peptide starting with Ser-42, at the proposed cleavage site of the human thrombin receptor. The protein kinase inhibitors staurosporine and H-7 blocked thrombin-induced retraction. It is therefore proposed that thrombin-mediated neurite retraction is caused by cleavage-induced activation of the thrombin receptor and involves stimulation of a protein kinase(s).
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PMID:Thrombin causes neurite retraction in neuronal cells through activation of cell surface receptors. 131 Aug 64

A polyclonal antibody, CR2, prepared using the C-terminal peptide of the alpha 1 subunit of the rabbit cardiac DHP-sensitive Ca channel, specifically immunoprecipitated the [3H]PN200-110-labeled Ca channel solubilized from cardiac microsomes. The antibody recognized 250 and 200-kDa cardiac microsomal proteins as determined by immunoblotting, and cAMP-dependent protein kinase phosphorylated the 250-kDa, but not the 200-kDa protein in vitro. CHO cells, transfected with the cardiac alpha 1 subunit cDNA carried by an expression vector, synthesized a 250-kDa protein which was recognized by CR2. Adding db-cAMP or forskolin to the transformed CHO cells induced phosphorylation of the 250-kDa protein and stimulated the DHP-sensitive Ba current under patch-clamp conditions. These results suggested that the cardiac DHP-sensitive Ca channel was regulated by cAMP-dependent phosphorylation of the alpha 1 subunit.
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PMID:Cyclic AMP-dependent phosphorylation and regulation of the cardiac dihydropyridine-sensitive Ca channel. 132 77

Two series of synthetic peptides that reproduce the amino- and carboxyl-terminal segments of the beta-subunit of casein kinase-2, including the sites phosphorylated by CK2 and cdc2 kinase, respectively, have been used as model substrates for these enzymes. The N-terminal peptide beta(1-9), MSSSEEVSW, is readily phosphorylated by CK2 but not all by cdc2. The opposite is true of the C-terminal peptide beta(206-215), NFKSPVKTIR, whose Ser-4 is a good target for cdc2 while being unaffected by CK2. The individual substitutions of Pro-5 and Lys-7 in the latter peptide with Gly and Ala (or Glu), respectively, prevent its phosphorylation by cdc2, whereas the substitution of Lys-3 with Ala is well tolerated and the substitution of the target Ser with Thr actually improves phosphorylation. Thus the consensus sequence for cdc2 is shown to be X-S-P-X-K. Such a requirement for a basic residue at position +3 is opposite to that of CK2 whose consensus sequence (S-X-X-E/D/Yp/Sp) includes an acidic residue at the same position. Moreover the motif Ser-Pro is detrimental for CK2, preventing the phosphorylation of otherwise suitable peptides. These observations would rule out the possibility that the site specificity of CK2 might overlap with that of cdc2 and possibly of other Pro-directed protein kinases.
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PMID:The consensus sequences for cdc2 kinase and for casein kinase-2 are mutually incompatible. A study with peptides derived from the beta-subunit of casein kinase-2. 145 79

cDNA clones coding for novel protein kinase C delta (nPKC delta) were isolated from a mouse brain cDNA library. Mouse nPKC delta consists of 674 amino acid residues and has sequence identity of 95% with rat nPKC delta. Antiserum raised against a C-terminal peptide of rat nPKC delta identified a 79-kDa protein in COS cells transfected with a mouse nPKC delta cDNA expression plasmid. nPKC delta expressed in COS1 cells had phorbol-ester-binding activity and protein kinase activity in a phorbol-ester- or diacylglycerol-dependent manner, like conventional protein kinase C (cPKC) isozymes and nPKC epsilon. However, nPKC delta, like nPKC epsilon, is not activated by Ca2+, a known activator of cPKCs, and requires lower concentrations of Mg2+ for full activation than cPKCs. Moreover, apparent kinetic constants for synthetic oligopeptides (MBP4-14, EGFR peptide and epsilon-peptide) were quite different between nPKC delta and cPKC in two different conditions. Among various phospholipids tested, phosphatidylinositol is the most potent activator of nPKC delta, in clear contrast to cPKCs and nPKC epsilon. Limited proteolysis of nPKC delta generated a C-terminal active fragment with a cofactor-independent kinase activity. Northern blot analysis indicated that nPKC delta, like cPKC alpha, is widely distributed in almost all the tissues and cells examined and, in some cases such as fibroblast cells, exists as a major PKC type. These results suggest that nPKC delta is involved in fundamental cellular functions regulated by diacylglycerols and mimicked by phorbol esters.
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PMID:Structure and properties of a ubiquitously expressed protein kinase C, nPKC delta. 176 3

Phosphorylation of avian gizzard caldesmon by casein kinase II was investigated. The enzyme incorporates about 1 mol of phosphate per mol of caldesmon. All sites of phosphorylation are located in short chymotryptic peptides with Mr 25-27 kDa or in the short N-terminal peptide formed after cleavage of chicken gizzard caldesmon at Cys153. The primary structure of the tryptic peptide containing the main site of duck gizzard caldesmon phosphorylation is S-E-V-N-A-Q-N-X-V-A-E-D-E-T-K, where X is an unidentified residue, presumed to be phosphoserine. Thus, Ser73 is the main site phosphorylated by casein kinase II in avian gizzard caldesmon.
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PMID:Identification of the site phosphorylated by casein kinase II in smooth muscle caldesmon. 191 49

Isolated interphase lamin C, obtained from Ehrlich ascites tumor cells, was digested by Lys-C endoproteinase, the resulting peptides separated by reversed-phase HPLC and subjected to microsequencing in order to identify phosphorylation sites in interphase and following phosphorylation in vitro by cdc2-kinase, protein kinase C (PKC) and protein kinase A (PKA), respectively. Nuclear lamin C showed partial phosphorylation of Ser392 and Ser409, and possibly Ser407 in interphase. Phosphorylation was increased in response to cdc2-kinase at Ser390 and Ser392 and to PKC at Ser572. The N-terminal peptide (aa 1-32) containing consensus sequences for the 3 kinases was phosphorylated by cdc2-kinase, PKC and PKA. The sequence data suggests that multiple molecular switches via lamina modification control the dynamic behaviour of the nucleoskeleton during the cell cycle.
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PMID:Identification of phosphorylation sites on murine nuclear lamin C by RP-HPLC and microsequencing. 195 8

The domain structure of duck gizzard caldesmon was investigated. A single thiol group is located in the vicinity of the C-terminus of the protein. A simple method for the purification of a short (21 kDa) C-terminal peptide formed after chemical cleavage of caldesmon at cysteine residues was evolved. The C-terminal peptide of caldesmon interacts with calmodulin with an affinity one order of magnitude higher than that of native caldesmon. The Ca2+/phospholipid-dependent protein kinase (protein kinase C) transfers about 2 mol of phosphate per mol of caldesmon. All sites phosphorylated by protein kinase C are located in the short (21 kDa) C-terminal peptide of caldesmon. Phosphorylation does not affect the interaction of caldesmon with calmodulin.
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PMID:Some properties of duck gizzard caldesmon. 198 78

As cells enter mitosis, the protein-tyrosine kinase, p60c-src, is known to be extensively phosphorylated on threonine in its amino-terminal region. In the present work, extracts of mitotic cells were searched for the protein kinase responsible for this phosphorylation. HeLa cells and Xenopus eggs were found to contain a mitosis-specific protein kinase activity capable of phosphorylating highly purified p60c-src in vitro on threonine residues. Tryptic phosphopeptide maps indicate that the mitotic HeLa kinase phosphorylates the same sites in vitro as those used during mitosis in vivo. In addition, this mitotic HeLa kinase comigrates on gel filtration with p34cdc2-associated histone H1 kinase, a well known regulator of mitotic events. Finally, antibodies to the C-terminal peptide of human p34cdc2 specifically deplete p60c-src-phosphorylating activity from mitotic extracts. These results suggest that p60c-src may act as an effector of p34cdc2 in certain mitotic processes.
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PMID:Mitosis-specific phosphorylation of p60c-src by p34cdc2-associated protein kinase. 247 May 13

The 18,000-dalton bovine lens fiber cell intrinsic membrane protein MP18 was phosphorylated on a serine residue by both cAMP-dependent protein kinase and protein kinase C. In addition, this protein bound calmodulin and was recognized by a monoclonal antibody (2D10). These different regions were localized using enzymatic and chemical fragmentation of electrophoretically purified MP18 that had been phosphorylated with either cAMP-dependent protein kinase or protein kinase C. Partial digestion of 32P-labeled MP18 with protease V8 resulted in a Mr = 17,000 peptide that bound calmodulin, but neither contained 32P or was recognized by the monoclonal antibody 2D10. Furthermore, the 17-kDa peptide had the same N-terminal amino acid sequence as MP18. Thus, the monoclonal antibody 2D10 recognition site and the protein kinase phosphorylation site(s) are close together and confined to a small region in the C terminus of MP18. This conclusion was confirmed in experiments where MP18 was fragmented with trypsin, endoproteinase Lys-C, or CNBr. The location of the phosphorylation site was confirmed by sequencing the small 32P-labeled, C-terminal peptide that resulted from protease V8 digestion of 32P-labeled MP18. This peptide contained a consensus sequence for cAMP-dependent protein kinase.
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PMID:Structural organization of the lens fiber cell plasma membrane protein MP18. 258 4


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