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:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein I has been identified and compared in membranes prepared from chick and rat forebrain. Based upon five criteria known to characterize protein I, namely, (1) its ability to serve as a substrate for both the cyclic AMP-dependent protein kinase and (2) the Ca2+- dependent, calmodulin-requiring protein kinase, (3) its ability to be extracted from membranes at low pH, (4) its characteristic pattern of digestion by collagenase, and (5) its existence as a basic protein, we have determined that although protein I of rat brain consists of the usual doublet polypeptides Ia and Ib, only a single chick forebrain polypeptide is detectable which possesses protein I-like properties.
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PMID:Identification and comparison of protein I in chick and rat forebrain. 631 4

Actomyosin was partially purified from rat parotid cells dispersed by collagenase digestion and found to possess different solubility characteristics from that from (undispersed) rat parotid tissue. This is attributed to the decrease in vascular contamination effected by the isolation of parotid cells, yielding a non-muscle actomyosin [Adelstein, Conti, Johnson, Pastan & Pollard (1972) Proc. Natl. Acad. Sci. U.S.A. 69, 3693-3697]. Myosin light-chain kinase was partially purified from dispersed rat parotid cells by calmodulin affinity chromatography and shown to be activated by Ca2+-calmodulin. The calmodulin content of dispersed rat parotid cells was shown to be 6.50 +/- 0.59 ng of calmodulin/micrograms of rat parotid-cell protein (mean +/- S.E.M.), as determined by the activation of purified bovine brain phosphodiesterase by heat-treated extracts of dispersed rat parotid cells.
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PMID:Studies on rat parotid-cell actomyosin. 633 11

Synapsin I (protein I) is a neuron-specific phosphoprotein, which is a substrate for cAMP-dependent and Ca/calmodulin-dependent protein kinases. In two accompanying studies (De Camilli, P., R. Cameron, and P. Greengard, and De Camilli, P., S. M. Harris, Jr., W. B. Huttner, and P. Greengard, 1983, J. Cell Biol. 96:1337-1354 and 1355-1373) we have shown, by immunocytochemical techniques at the light microscopic and electron microscopic levels, that synapsin I is present in the majority of, and possibly in all, nerve terminals, where it is primarily associated with synaptic vesicles. In the present study we have prepared a highly purified synaptic vesicle fraction from rat brain by a procedure that involves permeation chromatography on controlled-pore glass as a final purification step. Using immunological methods, synapsin I concentrations were determined in various subcellular fractions obtained in the course of vesicle purification. Synapsin I was found to copurify with synaptic vesicles and to represent approximately 6% of the total protein in the highly purified synaptic vesicle fraction. The copurification of synapsin I with synaptic vesicles was dependent on the use of low ionic strength media throughout the purification. Synapsin I was released into the soluble phase by increased ionic strength at neutral pH, but not by nonionic detergents. The highly purified synaptic vesicle fraction contained a calcium-dependent protein kinase that phosphorylated endogenous synapsin I in its collagenase-sensitive tail region. The phosphorylation of this region appeared to facilitate the dissociation of synapsin I from synaptic vesicles under the experimental conditions used.
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PMID:Synapsin I (protein I), a nerve terminal-specific phosphoprotein. III. Its association with synaptic vesicles studied in a highly purified synaptic vesicle preparation. 640 12

Human gallbladders were used to investigate the mechanisms of the impaired contraction induced by cholecystokinin (CCK) associated with cholesterol stones. Single muscle cells were isolated enzymatically with collagenase. Inositol 1,4,5-trisphosphate was measured by high-performance liquid chromatography. Diacylglycerol was assayed by thin-layer chromatography. CCK stimulation showed decreased muscle contraction and production of inositol 1,4,5-trisphosphate and diacylglycerol in gallbladders with cholesterol stones compared with those with pigment stones. Exogenous calmodulin induced maximal contraction of 22.4 +/- 0.5 and 21.0 +/- 0.6% in gallbladders with cholesterol and pigment stones, respectively. Similar findings were observed with a synthetic diacylglycerol analogue. Two G protein activators, aluminum fluoride and guanosine 5'-O-(3-thiotriphosphate), evoked similar responses in these two types of gallbladders, with maximal contractions of 21.3 +/- 0.4 and 23.3 +/- 0.5%, respectively, in those with cholesterol stones and 20.9 +/- 0.8 and 22.6 +/- 0.4%, respectively, in those with pigment stones. These results suggest that receptor-dependent ligands like CCK cannot fully activate the intracellular pathways, which, however, can be fully stimulated by circumventing receptors with G protein activators or second messengers. After G protein activation, the pathways appear to be functionally intact. The defect might then reside in the receptor or in the interaction between receptors and G proteins.
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PMID:Direct G protein activation reverses impaired CCK signaling in human gallbladders with cholesterol stones. 749 56

Pituitary cells were prepared by enzymatic dispersion and incubated in vitro. To observe the effect of gonadotropin releasing hormone (GnRH) and Ca2+ on the murrel pituitary cyclic 3',5'-AMP (cAMP), cells were dispersed by 0.3% collagenase plus 0.05% trypsin in Earle's minimum essential medium without Ca2+ and a considerably high yield of viable cells were obtained. Addition of a murrel, Channa punctatus, GnRH (cGnRH, 10 micrograms/incubation) to pituitary cell incubation (6 x 10(4) cells/well) containing 4 mM theophylline, a phosphodiesterase (PDE) inhibitor, stimulated cAMP accumulation in the pituitary cell 2.4-fold and its release into the medium about 2-fold as compared to control. The extent of stimulation was greatly increased on addition of Ca2+ (2 mM/incubation) with cGnRH: accumulation 5.8-fold and release 3.7-fold, respectively, in comparison to control. A time-course study with cGnRH (20 micrograms/incubation) plus Ca2+ (2 mM/incubation) on pituitary cell cAMP accumulation showed that the peak of cAMP level was reached at 15 min and remained at the same level until 60 min in the presence of theophylline; this peak was drastically reduced (5-fold) at 30 min in the absence of theophylline, indicating rapid hydrolysis of cAMP by PDE. Ca(2+)-augmented cGnRH stimulatory effect on cAMP accumulation and release could be significantly (P < 0.01) inhibited by verapamil (3 microM/incubation), a specific calcium channel blocker, suggesting requirement of extracellular Ca2+ influx in this process. Calmodulin (CaM), a Ca2+ carrier protein, addition to cGnRH and Ca2+ incubation further augmented the increase of cellular accumulation of cAMP and its release by 39.5 and 45%, respectively, in comparison to cGnRH and Ca2+ (both were statistically significant, P < 0.01). CaM effect could be blocked by calmidazolium (1 microM/incubation), a specific inhibitor of CaM, indicating specificity of the stimulatory action of CaM. Addition of radioiodinated 125I-CaM, in the presence of Ca2+ or cGnRH plus Ca2+ resulted in the binding of 125I-CaM to pituitary cells and to the pellet of the lysed cells. 125I-CaM specifically binds to pituitary cell plasma membrane preparation and saturation of 125I-CaM binding occurred at 9 ng of 125I-CaM. To investigate whether cGnRH plus Ca(2+)-stimulation of pituitary cells cAMP is linked to gonadotropin (GtH) release, similar protocols were followed. It was found that GtH release was augmented to 7-fold by cGnRH plus Ca2+, which was inhibited by verapamil and stimulated by CaM in a similar manner as observed in the case of cAMP.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Gonadotropin releasing hormone stimulation of cyclic 3',5'-AMP in the pituitary cell of a teleost (Channa punctatus, Bloch) requires extracellular calcium: its relationship to gonadotropin release. 778 50

We have identified, by differential cDNA library screening, 15 serum inducible genes in the human diploid fibroblast cell line WI-38. The genes fall into two classes that are distinguished by their dependence on protein synthesis for the induction by serum, i.e., primary and secondary genes. While 11 of these genes encode known proteins, 4 other genes have not been described to date. The former genes encode proteins of diverse functions, including the monocyte-derived neutrophil chemotactic factor (MONAP), calmodulin, tropomyosin, tenascin, collagenase, plasminogen activator inhibitor-2a, the 'sperm-specific' cleavage signal-1 protein, metallothionein IIa and the mitochondrial chaperonin hsp-60. Interestingly, one of the unknown genes contains a large open reading frame for a polypeptide that is highly homologous to a previously unidentified long open reading frame in the opposite strand of the gene coding for the transcription factor HTF-4. We also studied the regulation of these serum-induced genes during cell cycle progression in normally cycling WI-38 and HL-60 cells separated by counterflow elutriation as well as in serum-stimulated HL-60 cells. Our results clearly show that, in contrast to the prevailing opinion, the expression of most genes induced after mitogen stimulation is not subject to a significant regulation in normally proliferating cells. This supports the hypothesis that the progression into S from either G0 or G1 are distinct processes with specific patterns of gene expression.
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PMID:Identification of serum-inducible genes: different patterns of gene regulation during G0-->S and G1-->S progression. 800 57

Exocytosis of the secondary (2 degree) lysosomal granule is an important process in the activation of human neutrophils. Stored enzymes such as collagenase and gelatinase are released, and adhesion molecules from the granule membrane are inserted in the plasma membrane. This exocytosis is independent of azurophil granule release and respiratory burst activation. We investigated, using kinase and phosphatase inhibitors and activators of adenylate cyclase, common intracellular signalling mechanisms involved in exocytosis (vitamin B12 binding protein release) stimulated by different agonists. Exocytosis in response to tumour necrosis factor alpha (TNF alpha), phorbol myristate acetate (PMA) and the chemotactic tripeptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) was inhibited by the calmodulin antagonist N-(6-amino hexyl)-5-chloro-1-naphthalene sulphonamide (W7). Neither staurosporine, H7 nor genistein was inhibitory. In contrast, the same doses of W7 synergistically enhanced the exocytosis stimulated by the tyrosine phosphatase inhibitor sodium orthovanadate, while kinase inhibition by staurosporine or genistein dose-dependently inhibited the vanadate response. Furthermore, adenylate cyclase activation with prostaglandin E2 or dibutyryl cyclic AMP, inhibited exocytosis in response to TNF alpha and FMLP, while having no effect on the release induced by vanadate or PMA. Thus, 2 degree granule exocytosis stimulated by receptor-bound ligands is calmodulin-dependent, and is independent of protein kinase activity. In contrast, exocytosis in response to tyrosine phosphatase inhibition is antagonised by calmodulin, since the response to vanadate was enhanced synergistically by W7. Thus, depending on the initial stimulus, calmodulin may promote or inhibit 2 degree granule exocytosis by human PMN.
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PMID:Human neutrophil secondary granule exocytosis is independent of protein kinase activation and is modified by calmodulin activity. 892 8

The signal transduction that mediates CCK-induced contraction of gallbladder muscle was investigated in the cat. Contraction was measured by scanning micrometry in single muscle cells isolated enzymatically with collagenase. Production of D-myo-inositol 1,4, 5-trisphosphate (IP3) and sn-1,2-diacylglycerol (DAG) was quantitated using HPLC and TLC, respectively. Protein kinase C (PKC) activity was determined by measuring the phosphorylation of a specific substrate peptide from myelin basic protein, Ac-MBP-(4-14). CCK-induced contraction was blocked by incubation in strontium medium, pertussis toxin (PTx), and antibodies against Gialpha3 or betagamma-subunits but was not blocked by Ca2+-free medium or by antibodies against Gq/11alpha, Gialpha1-2, or Goalpha. The contraction induced by CCK was inhibited by the phospholipase C (PLC) inhibitor U-73122, anti-PLC-beta3 antibody, and the IP3 receptor antagonist heparin but was not inhibited by the the phospholipase D inhibitor propranolol or antibodies against PLC-beta1 or PLC-beta2. Western blot analysis of gallbladder muscle revealed the presence of PLC-beta2 and PLC-beta3 but not PLC-beta1. CCK caused a 94% increase in IP3 generation and an 86% increase in DAG generation. A low dose of CCK caused PKC translocation, and CCK-induced contraction was blocked by the PKC inhibitor H-7. A high dose of CCK, however, caused no PKC translocation, and its contraction was blocked by the calmodulin antagonist CGS9343B. In conclusion, CCK contracts cat gallbladder muscle by stimulating PTx-sensitive Gi 3 protein coupled with PLC-beta3, producing IP3 and DAG. Low doses activate PKC, whereas high doses activate calmodulin.
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PMID:Signal transduction pathways mediating CCK-induced gallbladder muscle contraction. 968 46

The effects of prostaglandin E2 (PGE2) on the proliferation and differentiation of osteoblastic cells were studied in osteoblast-like cells isolated from adult rat calvaria. Treatment of the cells with PGE2 within the concentration range 10(-8)-10(-5) M resulted in a dose-dependent increase in alkaline phosphatase (ALP) activity, [3H]proline incorporation into collagenase-digestible protein, and mineralized bone nodule (BN) formation, as well as a dose-dependent decrease in [3H]thymidine incorporation into the cells. PGE2 also caused a dose-dependent increase in the intracellular cyclic adenosine monophosphate (cAMP) content, with a maximal effective concentration of 10(-5) M; this effect of PGE2 was mimicked by forskolin, an adenylate cyclase activator. The treatment of adult calvarial cells with forskolin decreased BN formation, ALP activity, and collagen synthesis. These results suggested that cAMP does not have a stimulatory, but rather a suppressive, effect on the differentiation of adult rat calvarial cells. A time-course study of cAMP accumulation showed that both PGE2- and forskolin-induced cAMP reached a maximum at 5 min after the treatment, but the former rapidly returned to the basal level by 40 min, while the latter declined slowly and was still at 70% of the maximal level at 60 min, suggesting that PGE2 activates phosphodiesterase as well as adenylate cyclase. The presence of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), a calmodulin antagonist, reduced the rate of degradation of cAMP formed after PGE2 treatment, suggesting the involvement of calmodulin in the activation of phosphodiesterase. However, PGE2 also caused the production of inositol 1,4,5-triphosphate (IP3) and an elevation of the intracellular Ca2+ concentration ([Ca2+]i), both of which peaked at 15 s and returned to the basal level within 1 min. Submaximal responses of the IP3 production and the [Ca2+]i elevation to PGE2 were obtained at 10(-5) M. W-7 decreased both basal and PGE2-induced ALP activity, collagen synthesis and BN formation, indicating the involvement of Ca2+/calmodulin-dependent protein kinase in the PGE2-induced differentiation of calvarial cells. From these results, we concluded that PGE2 inhibits the proliferation and stimulates the differentiation of calvarial osteoblasts by elevating the [Ca2+]i through the activation of a phosphoinositide turnover, but not via an activation of adenylate cyclase. We also found that BN formation varies, depending on the time of PGE2 addition, suggesting that responsiveness of the cells to PGE2 may change during the culture period.
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PMID:Prostaglandin E2 stimulates the formation of mineralized bone nodules by a cAMP-independent mechanism in the culture of adult rat calvarial osteoblasts. 1008 22

Increasing evidence has indicated that bile canalicular contraction is mediated by the nonmuscular Ca(2+)-calmodulin-actomyosin system, and the contraction facilitates canalicular bile flow. The aim of the present study was to examine, by electron cytochemistry, how the expression of two types of plasma membrane Ca(2+)-ATPase, i.e., Ca(2+)-Mg(2+)-ATPase and Ca(2+)-pump-ATPase, is related to the dynamic changes of bile canalicular contraction. Hepatocytes isolated from male Wistar rat liver by collagenase perfusion were cultured to form a primary monolayer. The canalicular dynamics in the couplets and triplets were analyzed by time-lapse cinematography. The Ca(2+)-Mg(2+)-ATPase activity was identified by the electron cytochemical method of Ando. Ultrastructural localization of Ca(2+)-pump-ATPase was examined by immunogold electron microscopy. We found that cytochemical reaction products showing the presence of Ca(2+)-Mg(2+)-ATPase activity were localized on the luminal side of the bile canalicular membranes. Immunogold particles, indicating the presence of Ca(2+)-pump-ATPase, were located mainly on the cytoplasmic side of the bile canalicular membranes. The expression of both Ca(2+)-ATPases on the canalicular membranes was enhanced during the contracting stage of bile canaliculi, whereas their expression was diminished in the dilating stage. We conclude that two different types of bile canalicular Ca(2+)-ATPase may be involved in the regulation of canalicular contractility to control the extrusion of intracytoplasmic free calcium ions into the canalicular lumen.
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PMID:Bile canalicular contraction and dilatation in primary culture of rat hepatocytes--possible involvement of two different types of plasma membrane Ca(2+)-Mg(2+)-ATPase and Ca(2+)-pump-ATPase. 1168 60


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