Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Solid-phase enzyme immunoassay estimated S and C protein levels in 10 patients with nonspecific aortic arteritis (NAA). Lowered concentrations of total protein S (< 70%) occurred in 8 (80%) of 10 NAA patients, in 3 of them protein C was also low. Isolated reduction of protein C was encountered only in one patient. Four patients (44%) of 9 had antibodies to phospholipids, as a rule, in low concentrations. 3 of them had low total protein S concentrations against normal C protein. 4 patients (40%) showed elevated concentrations of WF antigen concentrations. No relationship was noted between a fall in total protein S, C concentrations and clinical presentation of NAA, the disease activity, presence of antibodies to neutrophil cytoplasm and antibodies to endothelial cells. Thus, a reduction in the levels of total protein S in NAA patients is induced by endothelial dysfunction unrelated to production of antibodies to phospholipids, neutrophil cytoplasm and vascular endothelium.
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PMID:[The clinical importance of determining protein C and protein S in patients with nonspecific aortoarteritis]. 932 92

Mutations in the gene for the cardiac isoform of myosin binding protein C (MyBP-C) have been identified as the cause of chromosome 11-associated autosomal-dominant familial hypertrophic cardiomyopathy (FHC). Most mutations produce a truncated polypeptide that lacks the sarcomeric binding region. We have now investigated the expression pattern of the cardiac and skeletal isoforms of cMyBP-C in mice and humans by in situ hybridization and immunofluorescence microscopy using specific antibodies and probes. We demonstrate that the cardiac isoform is expressed only in cardiac muscle throughout development. The slow and fast isoforms of MyBP-C remain specific for skeletal muscle, where they can be coexpressed. Immunological evidence also suggests that an embryonic isoform of MyBP-C precedes the expression of slow MyBP-C in developing skeletal muscle. This suggests that transcomplementation of MyBP-C isoforms is possible in skeletal but not cardiac muscle.
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PMID:Isoform transitions of the myosin binding protein C family in developing human and mouse muscles: lack of isoform transcomplementation in cardiac muscle. 944 Jul 11

The contributions from the secondary structure of the transcriptional activator protein C of bacteriophage Mu to its specific DNA binding and the influence of various factors, viz., electrolytes, and minor groove and major groove binders on this protein-DNA interaction have been addressed. Circular dichroism (CD) spectral results suggest that, in the absence of Mg2+, C protein exhibits a beta-pleated sheetlike structure and Mg2+ changes the conformation to a more alpha-helical structure which could provide specific geometrical constraints complementary to those of DNA-helix. Thus, Mg2+ acts as a cofactor for the binding of the C protein to its specific site in DNA by inducing conformational changes in the protein. Competitive binding studies with minor and major groove binding drugs, viz., distamycin A and methyl green, respectively, and the DMS footprinting data indicate that the C protein recognizes the major groove of DNA during complex formation. Further, upon major groove binding, C protein brings about changes in DNA conformation; such conformational changes could have implications in the transcription process.
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PMID:Mg2+ mediated sequence-specific binding of transcriptional activator protein C of bacteriophage Mu to DNA. 952 3

We have developed a new strategy with a very tight control for the expression of cloned genes. The system employed here is the T7 promoter-based expression system in which transcription activator protein C of bacteriophage Mu (Mu C) has been cloned to serve as a repressor in the regulatory circuit. The system also includes pLysE, which encodes T7 lysozyme, an inhibitor of T7 RNA polymerase. This ensures tight regulation of cloned genes in the uninduced state. Upon induction, the expressed Mu C protein binds to its cognate site thereby repressing lys transcription driven by the tet promoter. In order to evaluate the tight control achieved in the system, and to check leaky expression, if any, we have cloned the gene for the SmaI restriction endonuclease without its cognate methylase. For this purpose, a dicistronic unit was constructed by cloning the smaIR gene downstream of the Mu C gene. SmaI expression was observed only in the induced cell extracts, demonstrating a tight control. The system could be used to express the genes of other cloned restriction enzymes and has the potential for general applications.
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PMID:Design of a novel regulatory circuit for expression of restriction endonucleases. 962 59

Cardiac myofilaments contain proteins that regulate the interaction between actin and myosin. In the thick filament, there are several proteins that may contribute to the regulation of the contraction. The myosin binding protein C, or C protein, has 4 sites that can be phosphorylated by a Ca2+-calmodulin-controlled kinase, protein kinase A or protein kinase C. Using electron microscopy and optical diffraction, we examined the structure of thick filaments isolated from rat ventricles with either the alpha or beta isoform of myosin heavy chain (MHC) and the effect of specific phosphorylation of C protein on the structure. In thick filaments with alpha-MHC, crossbridges were clearly visible. Phosphorylation of C protein by protein kinase A extended the crossbridges from the backbone of the filament, changed their orientation, increased the degree of order of the crossbridges, and decreased the flexibility of the crossbridges. Crossbridges in filaments with beta-MHC were less ordered and apparently more flexible. Phosphorylation of C protein in beta-MHC-containing filaments did not extend the crossbridges and did not alter degree of order or flexibility. The relative flexibility of the crossbridges inferred from the optical diffraction pattern correlated well with the rate of ATP hydrolysis by actomyosin. These results suggest that (1) crossbridge flexibility is an important parameter in setting the rate of crossbridge cycling, and (2) C protein-mediated control of the position and flexibility of crossbridges may regulate actomyosin ATPase activity by modifying the kinetics of crossbridge cycling.
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PMID:Relation between crossbridge structure and actomyosin ATPase activity in rat heart. 967 Sep 19

The initial finding of an increased risk of venous thromboembolism in users of third-generation oral contraceptives (OCs) has not been confirmed in recent, more methodologically refined studies. This article reviews 17 prospective studies with healthy volunteers and one cross-sectional study that compared second- and third-generation OCs in terms of their effects on markers of hemostasis. Significant changes from baseline were reported for many variables with both second- and third-generation OCs. For example, activated partial prothrombin clotting time, protein S, and tissue plasminogen activator and its inhibitor were reduced during OC treatment. However, none of the studies reported statistically significant differences between treatment groups for any of these markers. In a combined analysis of nonsignificant changes, no consistent pattern emerged for any coagulation or fibrinolysis parameter with the exception of higher factor VII levels (not related to venous thromboembolism risk) associated with third-generation formulations. The cross-sectional study with an unvalidated assay found a higher ratio of activated C protein sensitivity with third-generation OCs. Only two components of the hemostatic system--factor VII and activated protein C sensitivity ratio--emerged as potentially differentially affected by second- and third-generation OCs. The association with venous thromboembolism risk is questionable in the former cases and unknown in the latter.
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PMID:Effects on hemostatic variables of desogestrel- and gestodene-containing oral contraceptives in comparison with levonorgestrel-containing oral contraceptives: a review. 975 11

The laboratory diagnosis of resistance to activated C protein (APC-resistance) involves examination of the phenotype and genotype of this thrombophilia. For examination of the phenotype coagulation and chromogenic tests are used. Their essence is examination in the presence and absence of exogenous APC. While the result of the original coagulation examination of APC-resistance which uses the APTT principle is influenced by a number of factors, the sensitivity and specificity of the modification of this examination (dilution of the examined plasma sample by FV deficient plasma before making the test) in relation to detection of FV Leiden is almost 100% and eliminates the majority of limitations of the original examination. The chromogenic assessment of APC-resistance has similar advantages, however, it cannot differentiate between the heterozygous and homozygous form of FV Leiden. During examination of the genotype of subjects with APC-resistance the mutation of FV Leiden is detected in as many as 90%. The group of subjects with the phenotype of APC-resistance comprises in particular subjects with acquired APC-resistance caused by conditions which lead to a disbalance between procoagulation and anticoagulation proteins of haemostasis which influence the reactions of the applied laboratory examinations. The acquired phenotype of APC-resistance can be also associated with an increased risk of thrombosis and the clinical manifestations of this thrombophilia resemble the classical, FV Leiden conditioned APC resistance. Rarely also congenital causes of the phenotype of APC-resistance are encountered caused by another mutation than the Leiden mutation of gene FV. The concurrent examination of the patient's plasma with the original and modified coagulation test makes it possible to assess the inborn cause of APC-resistance (positive finding also in modified examination). The presence of FV Leiden is then confirmed by examination of the genotype by the polymerase chain reaction.
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PMID:[Analysis of phenotype resistance to activated protein C (APC resistance)]. 1095 49

Hereditary hypercoagulability has been identified as risk factor in approximately 30% of cerebral venous thrombosis cases. We report three females with this association. A 38 years old female with a history of deep venous thrombosis of the lower limb, presented with headache, vomiting and a generalized seizure. Magnetic resonance angiography showed a partial thrombosis of the left lateral and superior longitudinal venous sinuses. Coagulation study showed a resistance to activated C protein and factor V Leyden. A 42 years old woman with a history of deep venous thrombosis, presented a right hemiplegia during a hospitalization. Magnetic resonance showed a left lateral hemorrhagic infarction. Magnetic resonance angiography showed an absence of signal in three venous sinuses. Coagulation study showed a protein C deficiency. A 17 years old woman presented a right hemiparesis in the sixth day of puerperium. CAT scan showed a left frontoparietal subcortical venous infarction. Coagulation study showed an antithrombin III deficiency.
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PMID:[Status of hereditary hypercoagulability and cerebral venous thrombosis. Report of 3 cases]. 1196 66

A study was carried out on activity of protein C4 in 73 surgical patients (coagulation test, reagents of company PEHAM). The reduction in activity of protein C was observed in patients with focal liver lesion related to disturbance of protein formation function. This percent of disturbances in protein C system is more often found in patients with vascular pathology. This is explained by the mechanism of its action and implication of vascular endothelium into the process. Disturbances in patients with injury infection are stipulated with activity of C and S proteins and availability of mutant factor V--factor Leiden in patients with diabetes. In the first days after surgical intervention the activity of C protein was much reduced. The obtained results emphasize the importance of research in the system of protein C in surgical patients.
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PMID:[Disorders of protein C anticoagulant system in various clinical conditions]. 1251 42

The anaphase-promoting complex or cyclosome (APC/C) is a cell-cycle-regulated ubiquitin-protein ligase that has been extensively studied in both fungal and animal cells. Many APC/C protein targets have been identified, and their sequential degradation during the cell cycle is essential for chromatid separation and mitotic exit. APC/C-dependent ubiquitylation of proteins not involved in cell-cycle progression has also been documented in animal cells. By contrast, the plant APC/C's structure and functions remained unexplored until recently. Here, we discuss recent developments in this field and explore the Arabidopsis genome sequence to identify plant APC/C components. Details of the APC/C ubiquitylation pathway in Arabidopsis are also available on a website that will be regularly updated.
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PMID:First glance at the plant APC/C, a highly conserved ubiquitin-protein ligase. 1259 75


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