Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) was evaluated for its ability to distinguish acrosome-intact from acrosome-damaged stallion spermatozoa. Incubation of fresh (acrosome-intact) and frozen-thawed (acrosome-damaged) spermatozoa with FITC-PSA resulted in acrosome-intact spermatozoa that exhibited no fluorescence, while acrosome-damaged spermatozoa exhibited fluorescent staining over the rostral portion of the head and equatorial segment. Experiments using mixtures of various ratios of acrosome-intact and acrosome-damaged spermatozoa determined the precision (intrasample coefficient of variation), and linearity (increased percentage of spermatozoa with PSA binding, with increased percentage of frozen-thawed spermatozoa in a sample) of FITC-PSA binding. The binding of FITC-PSA increased in samples as the portion of frozen-thawed (acrosome-damaged) to fresh (acrosome-intact) spermatozoa increased. A positive correlation existed (r = 0.98, P less than 0.05) between the percentage of FITC-PSA bound sperm and the proportion of damaged spermatozoa added to a sample. Location of PSA lectin binding on acrosome-damaged spermatozoa, determined by electron microscopy using gold-conjugated PSA, was to components of the outer acrosomal membrane and acrosomal matrix. These results demonstrate that FITC-PSA binding may be useful in determining acrosomal integrity of fresh and frozen-thawed stallion spermatozoa.
Mol Reprod Dev 1992 May
PMID:Assessment of Pisum sativum agglutinin in identifying acrosomal damage in stallion spermatozoa. 151 46

The psaC gene, which encodes the 8.9 kDa iron-sulfur containing subunit of Photosystem I, has been sequenced from Synechocystis sp. PCC 6803 and shows greater similarity to reported plant sequences than other cyanobacterial psaC sequences. The deduced amino acid sequence of the protein encoded by the Synechocystis psaC gene is identical to the tobacco PSA-C sequence. In plants psaC is located in the small single-copy region of the chloroplast genome between two genes (designated ndhE and ndhD) with similarity to genes encoding subunits of the mitochondrial NADH Dehydrogenase Complex I. The 5' ndhE-psaC-ndhD3' gene arrangement of higher plants is only partially conserved in Synechocystis. An open reading frame (ORF) upstream of the Synechocystis psaC gene has 85% identity to the tobacco ndhE gene. Downstream of psaC there is a 273 bp ORF with 48% identity to the 5' portion of the tobacco ndhD gene (1527 bp). psaC, ndhE and the region of similarity to ndhD are present in a single copy in the Synechocystis genome. Part of the wheat ndhD gene was sequenced and used as a probe for the presence of the 3' portion of the ndhD gene. The wheat ndhD probe did not hybridize to Synechocystis or Anabaena sp. PCC 7120 genomic DNA, but did hybridize to Oenothera chloroplast DNA. These results indicate the complete ndhD gene is absent in two cyanobacteria, and raises the question of what role, if any, the ndhD gene product plays in the facultative heterotroph Synechocystis sp. PCC 6803.
Plant Mol Biol 1991 Apr
PMID:Partial conservation of the 5' ndhE-psaC-ndhD 3' gene arrangement of chloroplasts in the cyanobacterium Synechocystis sp. PCC 6803: implications for NDH-D function in cyanobacteria and chloroplasts. 190 69

Recently a new non-steroidal antiandrogen (Casodex) has been shown in animal experiments to possess a potent peripheral antiandrogen effect. In patients with advanced prostatic cancer however, this drug is not peripherally selectively active and blocked central brain androgen-receptors results in a rise of luteinizing hormone (LH) and testosterone (T). We treated 18 advanced prostatic cancer patients with 50 mg Casodex daily for a mean period of 42 weeks. There were no complete objective responses but partial responses were seen in a few patients. In 16 patients there was a greater than 50% reduction of pretreatment PSA levels. Endocrine evaluations showed a significant rise in LH, T and oestradiol (E), reaching peak values within the two first months with subsequent lowering of these levels afterwards but without returning to normal. The general tolerance of the drug was good, gynecomastia being the most frequent side-effect. Libido and potency, when present before start of therapy, were maintained in some patients. We conclude that this compound seems as effective as other antiandrogens, but with improved compliance, and shows less side effects in the management of advanced prostatic cancer.
J Steroid Biochem Mol Biol 1990 Dec 20
PMID:Clinical profile of a new non-steroidal antiandrogen. 212 36

Differentiation of mouse embryonal carcinoma cells to the parietal endoderm phenotype is associated with expression of PTH-responsive adenylate cyclase. A PTH-like protein (PLP), which binds to PTH receptors and activates adenylate cyclase in classical PTH target cells was recently isolated and cloned. We assessed whether the parietal endoderm phenotype is associated with the expression of PLP or its receptor. A 1.4-kilobase PLP transcript was detected in the mouse parietal endoderm cell line PYS-2. No hybridizing transcripts were evident in undifferentiated mouse embryonal carcinoma cells PSA-1 or F9. However, differentiation of these cells to parietal endoderm, either spontaneously (PSA-1) or by treatment with retinoic acid and dibutyryl cAMP (F9), resulted in expression of the 1.4-kilobase PLP message. Undifferentiated F9 cells displayed negligible specific binding of [125I]PLP-(1-34)amide. When F9 cells were induced to differentiate to parietal endoderm, specific binding sites for [125I]PLP-(1-34)amide were expressed in parallel with PLP-responsive adenylate cyclase. These receptors, like those in classical PTH target tissues, displayed identical affinity (Kd = 5.2 nM) for bPTH-(1-34) and hPLP-(1-34)amide; with binding capacity (Bmax) of 6.6 x 10(4) sites/cell. In the presence of retinoic acid, exogenous PLP substituted for dibutyryl cAMP in a concentration-dependent fashion in promoting the differentiation of F9 cells to parietal endoderm. Thus, both PLP mRNA and PLP receptors coupled to adenylate cyclase are expressed during the differentiation of mouse embryonal carcinoma cells. Increased cAMP levels produced by autocrine stimulation of PLP receptors by PLP may contribute to differentiation of embryonal carcinoma cells into parietal endoderm.
Mol Endocrinol 1990 Apr
PMID:Expression of a parathyroid hormone-like protein and its receptor during differentiation of embryonal carcinoma cells. 217 44

The plasma membrane is considered to play a major role in the development of resistance to anthracycline and vinca alkaloid drugs (pleiotropic resistance). Previous studies have reported an increase in plasma membrane carbohydrates in pleiotropic resistant cells compared with wild-type cells. The present study has utilized a panel of 11 lectins and the streptavidin-biotin histochemical technique in order to compare plasma membrane carbohydrates from wild-type Ehrlich ascites tumour cells with cells from daunorubicin and vincristine resistant sublines. While the lectins ConA, LCA, PSA, PNA after neuraminidase and WGA stained plasma membranes of daunorubicin-resistant cells to a significantly greater degree than those of wild-type cells, no difference was apparent between vincristine-resistant and wild-type cells. PWM and WGA after neuraminidase pretreatment showed similar staining of the wild-type and both resistant sublines, while SBA with and without neuraminidase pretreatment, HPA, DBA, LTA and UEA I demonstrated either very weak or negative reactions with all sublines. We conclude that the observed increase in plasma membrane carbohydrate found in anthracycline-resistant cells is possibly due to drug action during acquisition and maintainance of resistance, and, though conceivably of importance in the development of resistance towards anthracyclines, is without significance for the pleiotropic resistance phenotype itself.
Virchows Arch B Cell Pathol Incl Mol Pathol 1988
PMID:Lectin staining patterns of plasma membranes of daunorubicin and vincristine resistant Ehrlich ascites tumour cells. 245 73

From among a series of stable, aphidicolin-resistant mutant strains of mouse teratocarcinoma, derived from a multipotent parental line (PSA-1-80), three were selected for further study on the basis of their comparatively high degrees of resistance and elevated frequencies of spontaneous forward mutation to 6-thioguanine and ouabain resistance. Fluctuation tests confirmed that they were mutator strains. Since each of the three mutants was isolated after multiple rounds of selection, and since a variety of biochemical abnormalities were observed, it is likely that a number of mechanisms, probably consisting of overlapping subsets, determine the phenotypes. Abnormalities in the metabolism of the nucleotide substrates for polymerization are likely to be of major importance in mutants designated Aph-2 and Aph-3, as there were marked alterations in the dCTP and dATP pool sizes. The specific activity of DNA polymerase alpha was also increased. For the case of Aph-3, which exhibited the greatest (400-fold) increase in resistance to aphidicolin, a mutation in the structural gene for DNA polymerase alpha may be an additional important component, since in vitro assays revealed that the isolated enzyme was resistant to aphidicolin. For the case of Aph-1 however, only minor alterations in dNTP pools were observed, and there was no increase in the specific activity of DNA polymerase alpha or in the aphidicolin resistance of the isolated DNA polymerase alpha, suggesting yet another mechanism(s) underlying the aphidicolin resistance/mutator phenotype. All three mutants formed subcutaneous tumors in syngeneic mice; both Aph-1 and Aph-2 were multipotent; whereas Aph-3 was nullipotent.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Gen Genet 1987 Jun
PMID:Aphidicolin-resistant mutator strains of mouse teratocarcinoma. 311 23

In the absence of retinoic acid, PSA-G teratocarcinoma stem cells spontaneously differentiate at a moderate frequency into fibroblast-like cells. In the presence of retinoic acid and dibutyryl cyclic AMP, PSA-G stem cells differentiate into parietal endoderm cells. We prepared a cDNA library from undifferentiated PSA-G teratocarcinoma stem cells; this cDNA library was then screened for gene sequences which exhibit a reduction in expression during the differentiation of these stem cells. From ca. 1,000 clones screened, eight independent sequences were isolated. The level of expression of these cloned genes decreases by 3.0-fold to more than 10-fold after differentiation of PSA-G cells into fibroblast-like cells. After treatment of either PSA-G or F9 teratocarcinoma cells with retinoic acid and dibutyryl cyclic AMP for 72 h, the expression of seven genes is inhibited by two- to fourfold. This decrease of clone-specific transcripts can be detected within 12 h after the addition of retinoic acid. Hybridization-selection and in vitro translation experiments identified the proteins encoded by three of the cloned genes: pST 6-23 codes for a 89,000-dalton protein, pST 7-105 codes for a 41,000-dalton protein, and pST 9-31 codes for a 34,000-dalton protein. The 89,000-dalton protein encoded by pST 6-23 is a heat shock protein. In vitro transcription experiments demonstrate that the retinoic acid-mediated decrease in pST 6-135- and pST 1-68-specific RNA occurs at the transcriptional level and that dibutyryl cyclic AMP acts posttranscriptionally to further depress the levels of these RNAs.
Mol Cell Biol 1984 Oct
PMID:Isolation of cDNA clones for genes exhibiting reduced expression after differentiation of murine teratocarcinoma stem cells. 609 43

Complement-mediated release of soluble immune complexes and immune precipitates containing DNP-PSA and precipitating or non-precipitating porcine anti-DNP antibodies was studied. A decrease in the average size of soluble immune complexes indicating their fragmentation was observed during incubation in excess human serum, the extent of the complex release was found to be in direct proportion to the time of incubation. The effect was complement-dependent. In the second part of the study, complement-dependent solubilization of the immune precipitates of the precipitating antibody preparation was compared to the solubilization of the precipitates of the non-precipitating antibody formed in the presence of PEG. Although, both types of precipitates activated complement in about the same extent, complexes of non-precipitating antibody were solubilized much slower than those of the precipitating one. As avidity of both antibody preparations to the antigen was high, the observed differences in the rate of the complex solubilization probably reflected differences in the structure of the two types of complexes.
Mol Immunol 1982 Feb
PMID:Complement-mediated fragmentation of soluble and insoluble immune complexes containing porcine anti-DNP antibodies. 709 69

We have recently demonstrated that the biphasic action of androgens on LNCaP cell proliferation is opposite to their effect on apolipoprotein D (apo-D) secretion, the stimulation of apo-D secretion being associated with a steroid-induced inhibition of cell proliferation. To further characterize the control of apo-D expression in LNCaP cells, we studied basal as well as androgen-induced apo-D secretion in slowly proliferating, low-passage (LP; 20-29th) and rapidly proliferating high-passage (HP; 111-117th) cell cultures. For comparison, the androgen-induced stimulation of prostate specific antigen secretion was also investigated in LP and HP cell cultures. In the absence of androgens, basal cell proliferation of HP cells was significantly higher than that of LP cells, whereas apo-D secretion was higher in LP cells than in HP cells. Furthermore, the biphasic action of dihydrotestosterone and of the synthetic androgenic compound R1881 on apo-D release and cell proliferation was observed in both LP and HP cells. The stimulation of apo-D secretion was inversely related to that of cell proliferation and influenced by cell density. The inhibition of basal and androgen-induced cell proliferation by the calcium channel blocker nifedipine was also associated with an increase in apo-D secretion. The amount of PSA released and the sensitivity of its response to R1881 were increased in LP cells compared with HP cells. The present study thus demonstrates, for the first time, that apo-D secretion is inversely correlated to cell proliferation and cell density in the absence as well as in the presence of androgens in both LP and HP LNCaP human prostate cancer cells. This finding suggests that apo-D expression can be modulated not only by steroid hormones, but also by other factors involved in the control of cell proliferation.
J Steroid Biochem Mol Biol 1994 Nov
PMID:Inverse relationships between cell proliferation and basal or androgen-stimulated apolipoprotein D secretion in LNCaP human prostate cancer cells. 752 88

Homopolymeric alpha-2,8-linked sialic acid (PSA) has been found as a capsular component of sepsis- and meningitis-causing bacterial pathogens, and on eukaryotic cells as a post-translational modification of the neural cell adhesion molecule (NCAM). The polysaccharide is specifically recognized and degraded by a phage-encoded enzyme, the endo-N-acetylneuraminidase E (Endo NE). Endo NE therefore has become a valuable tool in the study of bacterial pathogenesis and eukaryotic morphogenesis. In this report we describe the molecular cloning of Endo NE and the expression of a functionally active recombinant enzyme. The cloned DNA sequence (2436 bp) encodes a polypeptide of 811 amino acids, which at the 5' end contains a totally conserved neuraminidase motif. Expressed in Escherichia coli, the enzyme migrates as a single band of approximately 74 kDa in SDS-PAGE. A central domain of 669 amino acid residues is about 90% homologous to the recently cloned Endo NF. Both phage-induced lysis of bacteria and the catalysis of PSA degradation by the recombinant enzyme are efficiently inhibited by a polyclonal antiserum raised against the intact phage particle. The C-terminal region seems to be essential to enzymatic functions, as truncation of 32 amino acids outside the homology domain completely abolishes Endo NE activity. Our data also indicate that the 38 kDa protein, previously assumed to be a subunit of the Endo NE holoenzyme, is the product of a separate gene locus and is not necessary for in vitro depolymerase activity.
Mol Microbiol 1995 May
PMID:Molecular cloning and functional expression of bacteriophage PK1E-encoded endoneuraminidase Endo NE. 756 5


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