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)

A complementary DNA (cDNA) library has been constructed in lambda gt 10 from poly(A)+ mRNA isolated from auxin-deprived strawberry receptacles. By differential plaque filter hybridization, a cDNA (lambda SAR5) to an auxin-repressed mRNA has been isolated. The expression of the auxin-repressed gene is studied at various stages of normal fruit development and in fruits of variant strawberry genotype using lambda SAR5 as a probe. Northern analyses of RNA isolated from pollinated and unpollinated fruits of various developmental stages revealed that mRNA corresponding to the lambda SAR5 clone is repressed during normal fruit development, and the level of lambda SAR5 mRNA is regulated by endogenous auxin. Furthermore, results with both normal and variant genotype strawberry fruit indicate that there is a positive correlation between growth of strawberry fruit and repression of mRNA corresponding to the lambda SAR5 clone. The lambda SAR5 cDNA has been sequenced and is 723 nucleotides in length. The deduced protein has 111 amino acid residues with a molecular mass of 12.5 kDa. The putative polypeptide starts at nucleotide position 20 and ends at 352. The molecular weight of the predicted polypeptide is in agreement with the molecular weight of the in vitro translated polypeptide of hybrid selected mRNA. A comparison of the nucleotide and deduced amino acid sequence of lambda SAR5 with nucleotide and protein sequences in data banks has not revealed any homology to known proteins.
Plant Mol Biol 1990 Feb
PMID:Molecular cloning and sequencing of a cDNA for an auxin-repressed mRNA: correlation between fruit growth and repression of the auxin-regulated gene. 210 87

1. Abundant senile plaques and neurofibrillary tangles in certain brain regions constitute the major neuropathological characteristics of Alzheimer's disease. Recent work has established that the amyloid beta protein, which is derived from a large precursor, constitutes the major constituent of plaque amyloid, whereas the microtubule-associated protein tau is a component of the paired helical filament, the major constituent of neurofibrillary tangles. 2. Multiple isoforms of amyloid beta protein precursor and tau protein are produced from a single gene through alternative RNA splicing. By Northern blotting amyloid beta protein precursor transcripts are found throughout central and peripheral tissues, whereas tau protein transcripts are only found in the nervous system. 3. In the central nervous system the cellular localization of amyloid beta protein precursor and tau protein transcripts is neuronal. The cells affected in Alzheimer's disease patients produce both types of transcripts; however, the various transcripts are also found in cells not affected in the course of the disease. At present, there exists no evidence to suggest that an overproduction of amyloid beta protein precursor or tau protein is the reason for plaque and tangle formation. The formation of the latter probably results from posttranslational events.
Cell Mol Neurobiol 1990 Mar
PMID:Molecular neuropathology of Alzheimer's disease: in situ hybridization studies. 211 May 5

The rate of gene conversions and double crossovers between transfected and integrated mu heavy chain immunoglobulin genes was measured in myeloma cells. The assay relies on correction of an integrated and defective mu heavy chain expression unit, present in a repeated head to tail array in the genome of the myeloma cell line J558L. Following electroporation of these cells with restriction fragments containing normal immunoglobulin sequences, targeted recombination events are identified by a complement-mediated haemolytic plaque assay measuring production of functional IgM. Recombination results in replacement of a segment of the target sequence with the exogenous sequence. Different crossover positions are possible, giving rise to alternative rearrangements of the target site. In the case of one of the recombinants we analysed, more than one of the repeated targets had undergone a conversion event. The efficiency of homologous recombination was shown to depend on the extent of homology between transfected and target DNA. A targeting efficiency of 1 x 10(-5) to 2 x 10(-5) was achieved when the exogenous DNA contained 10,000 bases of sequence homologous with the target.
J Mol Biol 1990 Jun 05
PMID:Replacement recombinant events targeted at immunoglobulin heavy chain DNA sequences in mouse myeloma cells. 211 9

The acute and chronic effects of basic fibroblast growth factor (bFGF) on transferrin (TF) secretion from Sertoli cells were investigated by using reverse hemolytic plaque assays which enabled the visualization of release from individual cells in culture. We found that acute treatment with bFGF stimulates the release of TF from some but not al Sertoli cells in cultures obtained from 20-day-old rats. Chronic treatment with this growth factor resulted in increases in overall cell number in cultures from animals of each age tested (8-20 days of age). In contrast, this long-term treatment decreased markedly the proportions of Sertoli cells that secreted TF but only in cultures from 10-day-old animals. When taken together, these findings of acute and chronic influences of bFGF on TF secreting cells support the possibility that bFGF not only contributes to the modulation of the day-to-day release of certain substances from Sertoli cells, but may also influence development of the portions of the cell population that secrete these substances.
Mol Cell Endocrinol 1990 Oct 22
PMID:Fibroblast growth factor modulates the release of transferrin from cultured Sertoli cells. 212 83

We have examined the pharmacology of the voltage-sensitive Ca2+ channels (VSCCs) that mediate gonadotropin secretion from primary cultures of rat pituitary cells, stimulated by either cell depolarization or by binding of gonadotropin-releasing hormone (GnRH). We also measured single-cell [Ca2+]i transients using fura-2 in gonadotropes identified by a reverse hemolytic plaque assay employing an antiserum to luteinizing hormone (LH). Cell depolarization evoked by either 50 mM K+ or 30 microM veratridine induced 2- to 6-fold increases in gonadotropin secretion over basal levels. GnRH caused 6- to 20-fold increases in follicle-stimulating hormone (FSH) and LH secretion, respectively, with maximal stimulation at 100 nM GnRH. K(+)- or GnRH-induced FSH release was largely prevented by co-incubation with 1 mM CdCl. Tetrodotoxin (TTX, 5 microM) prevented the veratridine-, but not the K(+)- or GnRH-induced, stimulation of FSH secretion. Nitrendipine (Ntd, 1 microM) produced 35-50% inhibition (NS) of both FSH and LH release stimulated by either 50 mM K+ or 100 nM GnRH. Ntd also inhibited the K(+)-induced [Ca2+]i rise (greater than 90%), as well as the secondary, plateau phase of the GnRH-induced elevation of [Ca2+]i (100% inhibition). Omega-conotoxin (omega-CgTx, 100 nM) partially suppressed FSH and LH release (NS) due to both K+ (33% each) and GnRH (44% and 18%, respectively). omega-CgTx showed variable effects on [Ca2+]i transients evoked by K+ or GnRH ranging from clear inhibition to no effect. We conclude that influx of extracellular Ca2+ is one of several fundamental events underlying the depolarization- or receptor-activated release of LH and FSH, and that this influx can be inhibited by dihydropyridine-sensitive ('L') Ca2+ channels. Two classes of L-channels may exist in gonadotropes, that differ in their sensitivity to omega-CgTx.
Mol Cell Endocrinol 1990 Jul 09
PMID:Nitrendipine and omega-conotoxin modulate gonadotropin release and gonadotrope [Ca2+]i. 217 Feb 11

The presence of viral genomes in the murine heart in experimental coxsackievirus B3 myocarditis was investigated by Northern blotting analysis. Four-week-old C3H/He mice were inoculated with coxsackievirus B3. After sacrifice, the hearts were divided into 3 parts. Total RNA was extracted from one part of the heart. The other two parts were used for investigation of histopathology and of virus titer by plaque assay. The 32P-labeled cDNA probe was derived from the 5' end sequence of the coxsackievirus B3 genome. Northern blot autoradiograms of heart RNA were positive for viral RNA until day 7 and negative after day 10 and in control (uninfected) hearts. Positive autoradiograms always had the strongest signal at about 7.4 kilobase, corresponding to the size of the complete genome of the virus. The viral genomes were detected earlier than the appearance of the histopathologic changes in the murine heart. This type analysis of the viral genome in the murine myocardium may be useful in evaluating the effects of specific drugs on experimental viral myocarditis at the level of the viral genome.
J Mol Cell Cardiol 1990 Sep
PMID:The viral genome in experimental murine Coxsackievirus B3 myocarditis: a Northern blotting analysis. 217 95

A prolactin cDNA was cloned from a cDNA expression library constructed from total RNA of bullfrog (Rana catesbeiana) adenohypophyses by immunoscreening with antiserum against bullfrog prolactin. The cDNA clone thus obtained contained a 249 bp insert. Using this clone as a probe, plaque hybridizations were performed and two additional clones obtained. These clones had a polyadenylation site different from that of the first obtained clone, suggesting that the 3'-untranslated sequence was heterogeneous in length. The longest clone contained 830 bp, which encoded part of the signal peptide and the entire sequence of mature prolactin. The deduced amino acid sequence was in good accord with that determined by direct protein sequencing of purified bullfrog prolactin. The length of the bullfrog prolactin mRNA was estimated by Northern blot analysis to be about 1.0 kb. Homologies of prolactin nucleotide and amino acid sequences between bullfrog and other vertebrates were 64 and 65% for man, 66 and 68% for pig, 61 and 52% for rat, 69 and 74% for chicken, and 50 and 35% for salmon respectively. Highly conserved regions reported for mammalian prolactins also existed in bullfrog prolactin. Homologies of nucleotide and amino acid sequences between prolactin and GH of bullfrog origin were 49 and 25% respectively. Using the cDNA, the content of prolactin mRNA in the pituitary glands of metamorphosing tadpoles was measured. Prolactin mRNA levels rose at the mid-climax stage, suggesting that the increase in plasma and pituitary prolactin levels known to occur at the climax stage accompanies the increase in prolactin synthesis.
J Mol Endocrinol 1990 Dec
PMID:Molecular cloning and nucleotide sequence analysis of complementary DNA for bullfrog prolactin. 228 40

A unique high molecular weight protein (240,000 mol wt) has been purified from isolated desmosomes of bovine muzzle epidermis, using low-salt extraction at pH 9.5-10.5 and gel-filtration followed by calmodulin-affinity column chromatography. This protein was shown to bind to calmodulin in a Ca2+-dependent manner, so we called it desmocalmin here. Desmocalmin also bound to the reconstituted keratin filaments in vitro in the presence of Mg2+, but not to actin filaments. By use of the antibody raised against the purified desmocalmin, desmocalmin was shown by both immunoelectron and immunofluorescence microscopy to be localized at the desmosomal plaque just beneath the plasma membrane. Judging from its isoelectric point and antigenicity, desmocalmin was clearly distinct from desmoplakins I and II, which were identified in the desmosomal plaque by Mueller and Franke (1983, J. Mol. Biol., 163:647-671). In the low-angle, rotary-shadowing electron microscope, the desmocalmin molecules looked like flexible rods approximately 100-nm long consisting of two polypeptide chains lying side by side. The similar rodlike structures were clearly identified in the freeze-etch replica images of desmosomes. Taken together, these findings indicate that desmocalmin could function as a key protein responsible for the formation of desmosomes in a calmodulin-dependent manner (Trinkaus-Randall, V., and I.K. Gipson, 1984, J. Cell Biol., 98:1565-1571).
 ...
PMID:Desmocalmin: a calmodulin-binding high molecular weight protein isolated from desmosomes. 241 34

Previous DNA sequence analysis of bleomycin-induced forward mutations in repackaged lambda phage has suggested SOS-dependent replicative bypass of oxidized apyrimidinic sites as a possible mechanism of mutagenesis. In order to evaluate this hypothesis further, frequencies of mutation to a clear-plaque phenotype were compared for bleomycin-damaged phage grown in various repair-deficient strains of Escherichia coli. Survival of bleomycin-damaged phage was virtually identical in all host strains. Studies in SOS-deficient strains indicated specific requirements for functional recA+ and umuC+ alleles in the generation of the majority of bleomycin-induced mutations, as well as a less stringent requirement for induction of the SOS response by ultraviolet irradiation of the host cells. These results are expected for mutagenesis resulting from apyrimidinic sites. However, the mutation frequency for bleomycin-damaged phage was the same whether the phage were grown in a wild-type strain or in strains deficient in apurinic/apyrimidinic repair endonucleases; this was true even for an nth-nfo-xth- strain lacking all three major apurinic/apyrimidinic endonucleases (endonuclease III, endonuclease IV, and exonuclease III). Likewise, phage grown in an endonuclease IV-overproducing strain showed the same mutation frequency as those grown in wild-type cells. These data suggest that either i) bleomycin-induced mutagenesis results from SOS-dependent bypass of lesions other than apyrimidinic sites or ii) the number of apyrimidinic sites available for SOS processing is virtually independent of the level of apurinic/apyrimidinic endonuclease activity in the cell. It is possible that a fraction of the apyrimidinic sites induced by bleomycin either are intrinsically resistant to repair or undergo secondary reactions that render them resistant.
Environ Mol Mutagen 1988
PMID:Mutagenesis of bleomycin-damaged lambda phage in SOS-deficient and repair endonuclease-deficient Escherichia coli. 245 58

Arginine vasopressin (AVP) potentiates corticotrope responses to CRH by increasing the percentage of target cells that secrete in a reverse hemolytic plaque assay for ACTH. The present studies were designed to test more specific effects of AVP and its second messengers on CRH binding to individual corticotropes. Spectrophotometric analyses of 560 corticotropes from fractions enriched to 90% by counterflow centrifugation showed a 30% increase in the average area of the dark blue label for biotinylated CRH after a 1-h exposure to 10 nM AVP or after activation of protein kinase-C [by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or L calcium channels (by Bay K 8644). In addition, computer analysis of the color of the label (wavelength 476-483) showed a 13% increase in saturation (intensity of the blue) and a 23% decrease in brightness (amount of white) after stimulation. The gray level readings of the blue color were also 18% lower after stimulation, which indicates an increase in density (less light transmitted). Taken together, the increases in label area and intensity indicated that activation of L calcium channels or protein kinase-C enhanced CRH binding by individual corticotropes. When mixed pituitary cell populations were analyzed for percentages of labeled cells, exposure to Bay K 8644, TPA, angiotensin II, or AVP resulted in 30-40% increases in the percentage of CRH-bound cells. Dual reactions for biotinylated CRH and ACTH showed that most of the added CRH-bound cells stored ACTH. The effect of exposure to two of the activators was not additive, however. If L calcium channels were blocked with nimodipine, the protein kinase-C-mediated enhancement in CRH binding and ACTH release was blocked, indicating that these actions are dependent on extracellular calcium. In contrast, nimodipine did not block the TPA-mediated enhancement of ACTH storage. These studies show that the potentiation of CRH-mediated ACTH release by AVP or angiotensin II may occur by the enhancement of CRH binding to individual corticotropes. This appears to promote the cytochemical detection of additional CRH-bound corticotropes which may stem from a reserve cell population that normally has levels of CRH receptors or ACTH stores below thresholds needed for detection. The source of these cells (from stem cells or multipotential cells) remains to be determined.
Mol Endocrinol 1989 Jan
PMID:Activation of protein kinase C and L calcium channels enhances binding of biotinylated corticotropin-releasing hormone by anterior pituitary corticotropes. 246 51


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