Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.16 (calcineurin)
17,112 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cattle brain cortex was homogenised in 0, 29 mol/1 sucrose and centrifuged at 101 000 X g. The supernatant contains the majority of 3 enzymes participating in protein turnover: cathepsin (EC 3.4.4.23), phosphoprotein phosphatase (EC 3.1.3.16) and acid phosphatase (EC 3.1.3.2). They were separated by chromatography on Sephadex G 200 in neutral buffer. The cathepsin was purified up to 380 fold by gel filtration on Sephadex and column electrophoresis. The pH optimum of cathepsin was 5.7. At 37 degrees C no decrease of activity was measurable during 30 min. The Km was found to be 2.75 mg/ml Casein Hammarsten. The molecular weight by gel filtration and exclusion-gel electrophoresis was about 45 000, corresponding to the cathepsin from human liver (Barrett, A.J. (1970) Biochem. J. 117, 601-607). The sedimentation constant 3.0 S20,W is comparable with the values of proteinase of different origin, and the composition is similar with respect to the high proportion of acidic amino acids. The phosphoprotein phosphatase can be further purified by chromatography on hydroxyapatite and by column electrophoresis. The pH optimum of phosphoprotein phosphatase was about pH 5.5. At 45 degrees C no decrease of activity was measurable during 20 min; the Km was 1.43 mg/ml casein isoelectric. The pH optimum of acid phosphatase was about 5.6. At 54 degrees C NO DECREASE OF ACTIVITY WAs measurable during 30 min; the Km was 2 mumol/1 for Sodium phenolphthalein diphosphate. All three enzymes slowly lost their activity during several weeks at - 4 degrees C, apparently by self digestion in the cold.
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PMID:[Cathepsin, phosphoprotein-phosphatase and acid phosphatase in the soluble fraction of the cattle brain cortex: purification and properties (author's transl)]. 0 48

The activities of type I protein phosphatases play a central role in eukaryotic cell cycle control. Here, we report the cloning and characterization from the flowering plant Arabidopsis thaliana of a cDNA clone named PP1-At which is highly homologous to protein phosphatase 1. The deduced amino acid sequence of PP1-At shows that the PP1-At protein is 318 amino acid residues long and has a molecular weight of 35,298 Da. The PP1-At protein has strong similarity to all other known protein phosphatase type 1 catalytic subunits. Approximately 62% of the amino acids are identical to type 1 protein phosphatases of rabbit, mouse, Saccharomyces cerevisiae and Schizosaccharomyces pombe. RNA blot analysis revealed a single mRNA species of approximately the same size as the cDNA isolated. The PP1-At-encoded mRNA of 1.3 kb is abundant in most vegetative Arabidopsis tissues, with the lowest level of expression in leaves. When transferred to the fission yeast S.pombe, the PP1-At-encoded protein can rescue a semidominant mutant, cold sensitive (cs) dis2-11, which under nonpermissive conditions is unable to complete chromosome disjunction.
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PMID:Complementation of the cs dis2-11 cell cycle mutant of Schizosaccharomyces pombe by a protein phosphatase from Arabidopsis thaliana. 131 61

Microscopic screening of a collection of cold-sensitive mutants of Saccharomyces cerevisiae led to the identification of a new gene, CDC55, which appears to be involved in the morphogenetic events of the cell cycle. CDC55 maps between CDC43 and CHC1 on the left arm of chromosome VII. At restrictive temperature, the original cdc55 mutant produces abnormally elongated buds and displays a delay or partial block of septation and/or cell separation. A cdc55 deletion mutant displays a cold-sensitive phenotype like that of the original isolate. Sequencing of CDC55 revealed that it encodes a protein of about 60 kDa, as confirmed by Western immunoblots using Cdc55p-specific antibodies. This protein has greater than 50% sequence identity to the B subunits of rabbit skeletal muscle type 2A protein phosphatase; the latter sequences were obtained by analysis of peptides derived from the purified protein, a polymerase chain reaction product, and cDNA clones. An extragenic suppressor of the cdc55 mutation lies in BEM2, a gene previously identified on the basis of an apparent role in bud emergence.
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PMID:CDC55, a Saccharomyces cerevisiae gene involved in cellular morphogenesis: identification, characterization, and homology to the B subunit of mammalian type 2A protein phosphatase. 165 38

S. pombe dis mutants block mitotic chromosome disjunction in a manner reminiscent of aneuploidy formation, and belong to three distinct genes, dis1-dis3. We cloned two independent genomic DNAs that complemented both the cold-sensitive and caffeine-hypersensitive phenotype of dis2-11. These genes, dis2+ and a suppressor sds21+, encode proteins (calculated MW 37,000) with similar predicted amino acid sequences. dis2+ and sds21+ have overlapping functions, and disruptants are lethal only when both genes are disrupted. The gene products identified by anti-dis2 serum are enriched in nuclei. By hybridization, we obtained two cDNA clones from mouse and one genomic clone from S. cerevisiae; the latter complements S. pombe dis2-11. These dis2+ and similar polypeptides of yeasts and mouse are found to be highly homologous (75%-90% identical) to rabbit protein phosphatase 1. The implications of these findings are discussed with regard to mitotic control.
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PMID:The fission yeast dis2+ gene required for chromosome disjoining encodes one of two putative type 1 protein phosphatases. 254 98

The amino acid sequences of mammalian protein phosphatase 1 and 2A were compared pairwise with every sequence in the National Biomedical Research Foundation protein sequence database using an exhaustive searching programme [Coulson et al., Comp. J. 30 (1987) 420-424]. The N-terminal half of the protein encoded by an open reading frame, orf 221, in bacteriophage lambda (nt 43,224-43,886 in the map of Daniels et al. [in Hendrix et al. (Eds.), Lambda II. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 1983, pp. 519-676] shows 35% identity to either protein phosphatase 1 or 2A in this region. If conservative replacements are included the overall homology rises to 49%. A gene in phi 80 also shows 35% identity with the mammalian protein phosphatases. The results indicate that orf 221 of phage lambda and the homologous phi 80 gene may encode protein phosphatases. The possible roles of protein phosphorylation in the propagation of bacteriophage are discussed.
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PMID:Segments of bacteriophage lambda (orf 221) and phi 80 are homologous to genes coding for mammalian protein phosphatases. 285 44

'Initial' and 'total' activities of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) were measured in cold-clamped samples of liver from rats at 2h intervals throughout the 24h light/dark cycle. Initial activities were obtained in microsomes (microsomal fractions) isolated and assayed in the presence of 100mM-KF, whereas 'total' activities were measured in microsomes prepared from the same homogenates but washed free of KF and incubated with exogenous partially purified rat liver protein phosphatase. The initial/total-activity ratio for HMG-CoA reductase underwent a diurnal cycle, which had a nadir 4h into the light phase (when initial activity was 28% of total activity) and a peak 12h later, i.e. 4h into the dark phase (when initial activity was 80% of total activity). These low and high points of the cycle were separated by gradual steady changes in the ratio. The characteristics of this diurnal cycle were different from those of the cycle observed for total activity, which had a plateau of high activity between 2 and 10h into the dark cycle preceded and succeeded by a very rapid increase and decrease, respectively, in the total activity of HMG-CoA reductase. The combination of the two cycles resulted in the dampening of the resultant cycle for the initial or effective activity of HMG-CoA reductase, such that the changes in initial activity around the beginning and and end of the dark phase were more gradual than would otherwise have been the case if the initial/total-activity ratio for HMG-CoA reductase were constant throughout the diurnal cycle. The physiological implications of the observed diurnal variation in the fraction of hepatic HMG-CoA reductase in the active form are discussed.
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PMID:Diurnal changes in the fraction of 3-hydroxy-3-methylglutaryl-CoA reductase in the active form in rat liver microsomal fractions. 608 94

The need for nonshivering heat production, a principal function of brown adipose tissue, is accentuated in neonates. Accordingly, brown fat in the rat exhibits a very pronounced process of morphological and functional maturation perinatally, reaches a peak in its differentiation and heat-generating capacity within 1-2 weeks after birth, and undergoes involutive changes later in life. The later process of dedifferentiation can be either prevented or reversed by exposing the animals to cold ambient temperature for a prolonged period of time (cold acclimatization). The regulation of both the tissue maturation processes and the superimposed acute heat production are hormone mediated. Thus, the hormone receptor system within the adipocyte membrane and the sequence of molecular events interconnecting the initial hormonal stimulus with its final intracellular effect(s) are of considerable importance. The brown adipocytes of developing rats possess adrenoreceptors that can be pharmacologically classified as beta 1 (linked to adenylate cyclase) and alpha 2 (possibly linked to guanylate cyclase), multiple forms of cyclic nucleotide dependent and independent protein kinases, a protein kinase inhibitor, and at least two distinct phosphoprotein phosphatases associated with three phosphoprotein phosphatase modulators. The characteristics and developmental alterations of these regulatory components were studied in considerable detail by our group during the past decade. The results uncovered several target systems for ontogenic modifications of hormonal responses. Strong support was obtained for the hypothesis that protein phosphorylation and dephosphorylation is a major molecular mechanism involved in the regulation of both the brown adipocyte function and its proliferative activity during ontogenic development.
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PMID:Mechanisms of hormonal regulations in brown adipose tissue of developing rats. 614 37

Osteoclasts are known to have a high acid phosphatase content. We have adapted the simple simultaneous mono-coupling azo-dye method of Grogg and Pearse to undecalcified bone sections. A cold embedding in a mixture of glycol and methyl methacrylate was shown to well preserve the enzyme activity. Sodium alpha-naphtyl phosphate (1 mg/ml) and fast violet B (2 mg/ml) are used in 0.1 M acetate buffer, pH 5.0. The addition of 1 mM L(+) sodium tartrate selectively inhibits the acid phosphoprotein phosphatase ("osteoblastic acid phosphatase") but not osteoclastic lysosomal acid phosphatase. Counterstaining with phosphomolybdic aniline blue WS leads to well contrasted sections, providing accurate measurements of osteoclast number.
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PMID:Histochemical identification of osteoclasts. Review of current methods and reappraisal of a simple procedure for routine diagnosis on undecalcified human iliac bone biopsies. 619 76

The IPL2 gene is known to be required for normal polarized cell growth in the budding yeast Saccharomyces cerevisiae. We now show that IPL2 is identical to the previously identified BEM2 gene. bem2 mutants are defective in bud site selection at 26 degrees C and localized cell surface growth and organization of the actin cytoskeleton at 37 degrees C. BEM2 encodes a protein with a COOH-terminal domain homologous to sequences found in several GTPase-activating proteins, including human Bcr. The GTPase-activating protein-domain from the Bem2 protein (Bem2p) or human Bcr can functionally substitute for Bem2p. The Rho1 and Rho2 GTPases are the likely in vivo targets of Bem2p because bem2 mutant phenotypes can be partially suppressed by increasing the gene dosage of RHO1 or RHO2. CDC55 encodes the putative regulatory B subunit of protein phosphatase 2A, and mutations in BEM2 have previously been identified as suppressors of the cdc55-1 mutation. We show here that mutations in the previously identified GRR1 gene can suppress bem2 mutations. grr1 and cdc55 mutants are both elongated in shape and cold-sensitive for growth, and cells lacking both GRR1 and CDC55 exhibit a synthetic lethal phenotype. bem2 mutant phenotypes also can be suppressed by the SSD1-vl (also known as SRK1) mutation, which was shown previously to suppress mutations in the protein phosphatase-encoding SIT4 gene. Cells lacking both BEM2 and SIT4 exhibit a synthetic lethal phenotype even in the presence of the SSD1-v1 suppressor. These genetic interactions together suggest that protein phosphorylation and dephosphorylation play an important role in the BEM2-mediated process of polarized cell growth.
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PMID:Control of cellular morphogenesis by the Ip12/Bem2 GTPase-activating protein: possible role of protein phosphorylation. 796 97

There is increasing evidence that the mechanisms controlling the eukaryotic cell cycle are regulated by protein phosphorylation/dephosphorylation cascades. The catalytic subunit of the protein phosphatase 1 is implicated genetically and biochemically in the complex network that regulates mitosis. To investigate further the cell division in plants, we have isolated and characterized two full-length cDNAs from Arabidopsis thaliana, PP1A-At1 and PP1A-At2, encoding polypeptides highly homologous to known protein phosphatase 1 (PP1). DNA gel blot analysis suggests that the protein phosphatases 1 might form a small gene family in Arabidopsis. Northern analysis shows that transcripts are present in all plant organs. In cell cultures, the PP1 mRNA levels are differentially affected by treatment with drugs that block cell division. The expression of PP1A-At1 in a Schizosaccharomyces pombe cdc25ts/wee1- double-mutant strain restores temperature sensitivity, showing that the Arabidopsis phosphatase gene is capable of interacting with genes that regulate the fission yeast mitotic apparatus. However, the dis2-11 S. pombe strain, which has a cold-sensitive allele of the phosphatase 1 gene, is not rescued by expression of the PP1A-At1 gene, suggesting that the plant cDNA is not a functional homolog of the fission yeast gene.
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PMID:A protein phosphatase 1 from Arabidopsis thaliana restores temperature sensitivity of a Schizosaccharomyces pombe cdc25ts/wee1- double mutant. 822 Apr 77


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