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:3.4.23.5 (cathepsin D)
4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two types of cathepsin D were purified from rat spleen by a rapid procedure involving an acid precipitation of tissue extract, affinity chromatography with pepstatin--Sepharose 4B and concanavalin-A--Sepharose 4B, and chromatography on Sephadex G-100 and DEAE-Sephacel. The purified major enzyme (85% of the cathepsin D activity after DEAE-Sephacel chromatography), termed cathepsin D-I, represented about a 1000-fold purification over the homogenate and about a 20% recovery. The purified minor enzyme (15%), termed cathepsin D-II, represented about a 900-fold purification and about a 3% recovery. Both enzymes showed four (pI: 4.2, 4.9, 6.1 and 6.5) and three (pI: 4.6, 5.6 and 5.8) multiple forms after isoelectric focusing, respectively. The purified enzymes appeared homogeneous on electrophoresis in polyacrylamide gel and had a molecular weight of about 44000. In sodium dodecylsulfate/polyacrylamide gel electrophoresis both enzymes showed a single protein band corresponding to a molecular weight of 44000. The enzymes had similar amino acid compositions except for serine, proline and methionine. Cathepsin D-I contained 6.6% carbohydrate, consisting of mannose, glucose, galactose, fucose and glucosamine in a ratio of 8:2:1:1:5 with a trace of sialic acid. The properties of purified enzymes were also compared.
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PMID:Cathepsin D of rat spleen. Affinity purification and properties of two types of cathepsin D. 44 74

The determinants on the cytoplasmic tail of the cation-dependent mannose 6-phosphate receptor (CD-MPR) required for lysosomal enzyme sorting have been analyzed. Mouse L cells deficient in the mannose 6-phosphate/insulin-like growth factor-II receptor were transfected with normal bovine CD-MPR cDNA or cDNAs containing mutations in the 67-amino acid cytoplasmic tail and assayed for their ability to target the lysosomal enzyme cathepsin D to lysosomes. Cells expressing the wild-type bovine CD-MPR sorted 67 +/- 2% of newly synthesized cathepsin D compared with the base-line value of 47 +/- 1%. The presence of mannose 6-phosphate in the medium did not affect the efficiency of cathepsin D sorting, indicating that the routing of the ligand-receptor complex is completely intracellular. Mutant receptors with the carboxyl-terminal His-Leu-Leu-Pro-Met67 residues deleted or replaced with alanines sorted cathepsin D below the base-line value. A mutant receptor with the outermost Pro-Met residues replaced with alanines sorted cathepsin D better than the wild-type receptor, indicating that the essential residues for sorting are the His-Leu-Leu sequence. Disruption of a putative casein kinase II phosphorylation site at Ser57 had no detectable effect on sorting. The mutant receptor with the five-amino acid deletion was able to bind to a phosphopentamannose affinity column, proving that its ligand binding site was grossly intact. Resialylation experiments showed that this mutant receptor recycled from the cell surface to the Golgi at a rate similar to the normal CD-MPR, indicating that the defect in sorting is at the level of the Golgi.
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PMID:A His-Leu-Leu sequence near the carboxyl terminus of the cytoplasmic domain of the cation-dependent mannose 6-phosphate receptor is necessary for the lysosomal enzyme sorting function. 132 23

17 beta-Estradiol stimulates the secretion of the 34- and 52-kDa protein (i.e., cathepsin D and procathepsin D, respectively) from MCF-7 human breast cancer cells and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits this estrogen-stimulated response. A comparison of the effects of 17 beta-estradiol, TCDD, and their combinations on the secretion of these two proteins was determined using four different assay procedures, namely autoradiographic analysis of the 35S-labeled proteins (from [35S]methionine) separated by polyacrylamide gel electrophoresis (PAGE), densitometric analysis of the silver- and double-stained proteins separated by PAGE, and radioimmunoassay of the proteins using commercially available antibodies to the 52-kDa protein. The results showed that the autoradiographic, staining, and radioimmunoassay procedures gave comparable results with only a few minor differences in the relative amounts of the 52-kDa detected in the various treatment groups. In the medium obtained from 17 beta-estradiol-treated cells that was serially diluted, there was an excellent linear correlation for the relative concentrations of the 52-kDa protein using the double-staining/densitometric procedure and the radioimmunoassay. These results indicate that the double- or silver-staining method may be a useful and rapid method for screening new compounds as antiestrogens in MCF-7 cells.
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PMID:Development of gel staining techniques for detecting the secretion of procathepsin D (52-kDa protein) in MCF-7 human breast cancer cells. 138 Nov 55

Progestins increase the activity and rate of synthesis of cathepsin D, a lysosomal aspartyl protease, in the uterine luminal epithelium in ovariectomized rats. Western blot analysis of luminal epithelial proteins determined that the progestin, medroxyprogesterone acetate (MPA) increased the 43-kDa form of cathepsin D by 7-fold in 24 hr, whereas estradiol increased the amount of the same form by only 2-fold. To examine the precursor-product relationship between cathepsin D proteins in the luminal epithelium and stroma-myometrium after progestin or estradiol treatment, uterine proteins were prelabeled by incubation with [35S]methionine in vitro, cathepsin D was isolated by immunoprecipitation, and equal amounts of labeled cathepsin D were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After each hormonal treatment in each uterine tissue, a 48-kDa precursor was processed into a 44-kDa cathepsin D product. Endoglycosidase H digestion of [35S]methionine-labeled cathepsin D from the luminal epithelium and stroma-myometrium of medroxyprogesterone-treated rats shifted the molecular masses of the cathepsin D proteins by approximately 5.7 kDa. To examine the contribution of increased mRNA to increased rates of cathepsin D synthesis, we measured levels of cathepsin D mRNA in uterine tissues after progestin and estrogen treatment. Total RNA was isolated from the uterine luminal epithelium and from the stroma-myometrium. Northern blot analysis identified a single 2.2-kb RNA band corresponding to the size expected for cathepsin D mRNA. Medroxyprogesterone increased levels of cathepsin D mRNA in the luminal epithelium (greater than 17-fold) and in the stroma myometrium (3-fold), with maximum increases at 9 hr after treatment. Estradiol also increased cathepsin D mRNA levels in both uterine tissues, but by only 2-fold. No hormonal effects on liver cathepsin D mRNA were observed. Increases in cathepsin D synthesis and activity in uterine tissues in response to progestin and estrogen appear to depend in part upon increased levels of mRNA.
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PMID:Progestin and estrogen control of cathepsin D expression and processing in rat uterine luminal epithelium and stroma-myometrium. 138 74

Ovarian cancers are highly invasive. In a first attempt to define the hormones and factors involved in the control of tumor invasion and metastasis, we have used the human ovarian cancer cell line BG-1 which contains both estrogen and progesterone receptors. Protein synthesis and secretion was assayed by [35S]methionine incorporation and polyacrylamide gel electrophoresis followed by fluorography. Three responses to estradiol were found: 1) procathepsin D secretion was increased, whereas the corresponding intracellular proteins were not significantly affected; 2) an abundant but nonidentified 120-kilodalton (kDa) estrogen-induced secreted glycoprotein, different from CA125, was detected for the first time; and 3) the number of cells as determined by DNA assay was markedly stimulated, reaching a higher level of confluency. The antiestrogen OH-tamoxifen was weakly agonist at low concentrations to stimulate cell growth but was a pure antagonist on the 120-kDa protein. The steroid specificity of these responses strongly suggests that they are mediated by the estrogen receptor. We conclude that cathepsin D secretion is specifically stimulated by estrogen in this ovarian cancer cell line as it is in estrogen receptor-positive breast cancer cells. Both cathepsin D and a newly described 120-kDa secreted glycoprotein are potential markers of hormone responsiveness and/or aggressiveness which deserve to be further studied in clinical ovarian cancers.
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PMID:Estradiol stimulates cell growth and secretion of procathepsin D and a 120-kilodalton protein in the human ovarian cancer cell line BG-1. 146 54

Thiol and aspartyl proteolytic activities in isolated secretory vesicles of neural (NL) and intermediate (IL) lobes of bovine pituitary were characterized with heterologous enkephalin and tachykinin precursor substrates, 35S-(Met)-preproenkephalin and 35S-(Met)-beta-preprotachykinin. IL and NL secretory vesicles contained thiol-dependent proteolytic activity that cleaved the enkephalin precursor with a pH optimum of 4.5; this activity resembled a novel "prohormone thiol protease' previously purified and characterized from adrenal medulla chromaffin granules. IL and NL vesicles also demonstrated aspartyl proteolytic activity with acidic pH optimum, as shown by pepstatin A inhibition of tachykinin and enkephalin precursor cleaving activity. This activity may be related to a previously characterized chromaffin granule aspartyl protease (CGAP) related to cathepsin D (2), as indicated by the presence of immunoreactive CGAP in NL secretory vesicles by anti-CGAP immunoblots. These results show that pituitary secretory vesicles, like chromaffin granules, may contain similar thiol-dependent and aspartyl proteolytic activities.
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PMID:Thiol and aspartyl proteolytic activities in secretory vesicles of bovine pituitary. 155 May 54

The biosynthesis, processing, and intracellular transport of lysosomal acid phosphatase was studied using an in vitro cell-free translation system, pulse-chase experiments with primary cultured rat hepatocytes and subcellular fractionation techniques of rat liver after pulse-labeling with [35S]methionine in vivo. The single polypeptide of 45 kDa translated in the cell-free system from membrane-bound polysomal RNAs was converted to the 64 kDa form when the translation was carried out in the presence of microsomal vesicles. Pulse-chase experiments using cultured rat hepatocytes showed that acid phosphatase is initially synthesized as an endo-beta-N-acetylglucosaminidase H (Endo H)-sensitive form of 64 kDa, and processed via an Endo H-sensitive intermediate form of 62 kDa to an Endo H-resistant form with a 67 kDa mass. Phase separation with Triton X-114 showed that both the 64 and 67 kDa forms have hydrophobic properties. Treatment of the cells with chloroquine or tunicamycin, drugs which enhance the secretion of lysosomal hydrolases, had no effect on the normal transport of acid phosphatase to lysosomes. Acid phosphatase did not contain the phosphorylated high mannose type of oligosaccharide chains observed in cathepsin D. Subcellular fractionation experiments in conjunction with pulse-labeling in vivo showed that the acid phosphatase of the 67 kDa form was present in the Golgi heavy fraction (GF3) and the Golgi light fraction (GF1+2) enriched in cis and trans Golgi elements, respectively, at 30 min after the administration of [35S]methionine. Simultaneously, this polypeptide was also found in the lysosomal membrane fraction, thereby indicating that acid phosphatase is delivered to lysosomes in a membrane-bound form, immediately after reaching the trans-Golgi region.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Biosynthesis, processing, and intracellular transport of lysosomal acid phosphatase in rat hepatocytes. 169 35

Native electrophoresis followed by imprint digest method using hemoglobin as substrate allowed the detection of parasite hemoglobinase activity at acidic pH (3.9 to 5). This protease was inhibited specifically by pepstatin A and insensitive to other protease inhibitors. The molecular weight determination using modified SDS-PAGE followed by imprint digest method, demonstrated a single area of activity at 55-58 kDa, similar to cathepsin D characterized in eucaryotic cells. The parasitic origin has been shown by radiolabeling experiments with [35S]-methionine. The 55-kDa protein was immunoprecipitated by a rabbit anti-cathepsin D serum.
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PMID:Plasmodium falciparum: isolation and characterization of a 55-kDa protease with a cathepsin D-like activity from P. falciparum. 201 66

The effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the growth of estrogen-responsive MCF-7 human breast cancer cells in the presence of 17 beta-estradiol was determined. After treatment with 17 beta-estradiol (1 nM), TCDD (10 nM) and 17 beta-estradiol (1 nM) plus TCDD (10 nM) the cells were monitored daily for cell growth and DNA content for 7 days. The results showed that TCDD inhibited cell proliferation and DNA content of untreated cells and inhibited the 17 beta-estradiol-stimulated cell proliferation and increase in cellular DNA content. In contrast, TCDD did not effect the growth of estrogen non-responsive MDA-MB-231 human breast cancer cells. TCDD (0.1-10 nM) also caused a concentration-dependent decrease in the 17 beta-estradiol-induced proliferation in MCF-7 cells. The effects of TCDD on the 17 beta-estradiol-induced secretion of the 52-kDa protein (i.e. procathepsin D), the 34-kDa (cathepsin D) and 160-kDa proteins were also determined in the MCF-7 and MDA-MB-231 human breast cancer cell lines. The levels of the proteins were determined by autoradiographic analysis of the incorporation of [35S]methionine into the secreted proteins which were separated by denaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Treatment of MCF-7 cells with 17 beta-estradiol (1 nM), TCDD (10 and 100 nM) and 17 beta-estradiol (1 nM) plus TCDD (10 nM) resulted in levels of the 52-kDa protein which were 497, 63.6, 98.1 and 66.3%, respectively, of the corresponding levels observed in control (untreated) cells. Using the same concentrations, the levels of the 34-kDa protein secreted into the media were 372, 42.3, 64.0 and 43.8% of control values, respectively, and the corresponding levels of the 160-kDa protein were 381, 52.9, 71.2 and 76.6% of the control values, respectively. In contrast, treatment of MDA-MB-231 cells with 17 beta-estradiol (1 nM), TCDD (10 and 100 nM) and 17 beta-estradiol (1 nM) plus TCDD (10 nM) resulted in a 31-39% reduction in the secretion of the 52-kDa protein however these effects were not statistically different from the control values. In addition, the treatments did not cause any significant effects on the secretion of the 34- and 160-kDa proteins by MDA-MB-231 cells. These results clearly confirm and extend the range of antiestrogenic effects caused by TCDD in estrogen-responsive MCF-7 cells and indicate that the MDA-MB-231 cells are not responsive to the antiestrogenic effects of TCDD.
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PMID:Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on cell growth and the secretion of the estrogen-induced 34-, 52- and 160-kDa proteins in human breast cancer cells. 227 56

The Mr 52,000 estrogen-induced protein secreted by MCF7 cells has been identified as a procathepsin D (procath D), which increases cell growth in vitro, may stimulate invasiveness by digesting extracellular matrix and appears to be a tissue marker for predicting relapses in breast cancer patients. The protease is also present within mammary cells as Mr 48,000, 34,000, 14,000 mature forms that were also recognized by the previously described antibodies to the Mr 52,000 protein (M. Garcia, F. Capony, D. Derocq, D. Simon, B. Pau, and H. Rochefort, Cancer Res., 45: 709-716, 1985). Using selective screening with a [35S]methionine-labeled MCF7 cell lysate, we have now isolated two new monoclonal antibodies interacting exclusively with the Mr 52,000 procath D. The two monoclonal antibodies, M2E8* and D9H8*, purified from ascitic fluids are IgG1. Their respective Kds for Mr 52,000 procath D are 0.96 and 0.18 nM. They are directed against two separate domains of the proenzyme that differ from the three domains of previously described antibodies. They both interact with the deglycosylated protein and recognize the autoactivated secreted proenzyme (Mr 51,000), which is devoid of the first part of the NH2-terminal end. By immunodetection of cathepsin D proteolytic activity in plasma, these two antibodies were found to recognize selectively human cathepsin D but not the cathepsin D of other species (rat, mouse, rabbit, goat, and horse) whereas antibodies to mature cathepsin D were less species specific. Using sequential passages on concanavalin A-Sepharose and Sepharose matrices coupled to antibodies to the precursor and antibodies to the mature cathepsin D, we separately purified to homogeneity the Mr 52,000 procath D form and its processed cellular forms, whose biological activities can now be assessed independently. The two monoclonal antibodies were also shown to inhibit the uptake and processing of the Mr 52,000 cathepsin D in MCF7 cells (mostly D9H8*) and to decrease its proteolytic activity, mostly on extracellular matrix (M2E8*). These two monoclonal antibodies are therefore new tools for studying the function, regulation, cellular processing, and localization of procath D as well as the clinical significance of its concentration in normal and tumoral mammary epithelial cells.
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PMID:Characterization and properties of two monoclonal antibodies specific for the Mr 52,000 precursor of cathepsin D in human breast cancer cells. 245 53


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