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At least 1,135 records · Page 63Linked to original sources
PubMed2000

Mouse testis brain ribonucleic acid-binding protein/translin colocalizes with microtubules and is immunoprecipitated with messenger ribonucleic acids encoding myelin basic protein, alpha calmodulin kinase II, and protamines 1 and 2.

Testis brain RNA-binding protein (TB-RBP) is a sequence-dependent RNA-binding protein that binds to conserved Y and H sequence elements present in many brain and testis mRNAs. Using recombinant TB-RBP and a highly enriched tubulin fraction, we demonstrate here that recombinant TB-RBP binds to microtubules assembled in vitro. The interaction between recombinant TB-RBP and microtubules was inhibited by high salt and by the microtubule disassembling agents colcemid and calcium, but not by the microfilament-disassembling agent cytochalasin D. Confocal microscopy confirmed colocalization of TB-RBP and tubulin in the cytoplasm of male germ cells. An affinity-purified antibody prepared against recombinant TB-RBP specifically precipitated mRNAs encoding myelin basic protein and alpha calmodulin-dependent kinase II-two transported mRNAs, and protamines 1 and 2-two translationally regulated testicular mRNAs. These data indicate an intracellular association between TB-RBP and specific target mRNAs and suggest an involvement of TB-RBP in microtubule-dependent mRNA transport in the cytoplasm of cells.

Amino Acid Sequence↗
PubMed2003

Agreements between the prothrombin times of blood treated In Vitro with heparinase during cardiopulmonary bypass (CPB) and blood sampled after CPB and systemic protamine.

UNLABELLED: The prothrombin time (PT) is useful for identifying coagulation factor deficits after cardiopulmonary bypass (CPB). However, long processing times and the need for fresh frozen plasma (FFP) to be thawed cause delays in factor replacement. We hypothesized that, by treating with heparinase, blood sampled toward the end of CPB can provide PT results that help to determine the requirement for FFP after CPB. Laboratory delays can be eliminated with point-of-care monitors. We studied 158 adults undergoing nonemergent cardiac surgery. Blood taken before separation from CPB was mixed with heparinase, and PT was measured in the laboratory with a HemoTec timer. Agreements between these results and laboratory measurements of blood taken after systemic protamine were compared by using Bland and Altman plots with the threshold of +/-1.0 s. We found that the laboratory PT measurements during CPB versus after CPB were compara-ble, but the limits of agreement exceeded these thresholds. Similarly, there was unsatisfactory agreement between the HemoTec and laboratory PT results measured before, during, and after CPB. For each PT measured during CPB, the corresponding confidence interval for the postprotamine PT was calculated. During CPB, a laboratory PT of < or =16 s or > or =18 s suggests a > or =83% or > or =93% probability of not requiring or potentially requiring, respectively, FFP after CPB. We conclude that the majority of PT measurements obtained from blood taken before weaning from CPB and treated in vitro with heparinase was associated with a high probability of whether or not FFP would be needed after CPB. IMPLICATIONS: Coagulation dysfunction after cardiopulmonary bypass may contribute to bleeding. Obtaining coagulation tests and fresh frozen plasma requires time and delays treatment in patients who need fresh frozen plasma. We have devised a technique to provide early estimation of postbypass coagulation status.

Aged↗
PubMed1994

Protamine neutralization of intravenous and subcutaneous low-molecular-weight heparin (tinzaparin, Logiparin). An experimental investigation in healthy volunteers.

The aim of the present study was to investigate whether tinzaparin sodium (a low-molecular-weight heparin (LMWH)) was fully and permanently neutralized in vivo in man by protamine sulphate (PS) after intravenous (i.v.) or subcutaneous (s.c.) injection. Fifty healthy adults equally divided in five age- and sex-matched groups were included. The groups received 50 IU unfractionated heparin (UH)/kg body weight (b.w.) i.v., 50 anti-factor Xa (anti-Xa) IU tinzaparin/kg b.w. i.v., 75 anti-Xa IU tinzaparin/kg b.w. s.c., 175 anti-Xa IU tinzaparin/kg b.w. s.c., or 1 ml of saline s.c. PS was given as a 10 min infusion in a dose of 1 mg/100 IU of heparin in the four first groups while 0.5 mg PS/kg b.w. was given in the placebo group. In the i.v. groups PS was administered 45 min after the heparin injection, and in the s.c. groups 180 min post-heparin injection. In the UH group PS fully and permanently neutralized all three activities. In the i.v. tinzaparin group PS reversed 80% of the anti-Xa activity, while the anti-IIa and aPTT activities were fully reversed. A slight, but statistically significant, increase in anti-Xa and anti-IIa activities were seen following i.v. tinzaparin. In the s.c. groups 60-65% of the observed peak anti-Xa activity was neutralized, anti-IIa was almost completely reversed, and aPTT returned nearly to baseline values. A gradual return of the anti-Xa activity (65-75%), anti-IIa activity (55%) and aPTT activity (35-45%) was seen in the s.c. groups 3 h after reversal compared with the observed peak values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Protamine 3'-untranslated sequences regulate temporal translational control and subcellular localization of growth hormone in spermatids of transgenic mice.

Although the mouse protamine 1 gene (mP1) is first transcribed in round spermatids, its mRNA is not translated until about 1 week later in elongating spermatids. To determine what mP1 sequences are important for its transcriptional and translational regulation, we have constructed fusions between mP1 and the human growth hormone (hGH) structural gene and analyzed their expression in transgenic mice. We show that mP1 sequences 5' to the start of transcription are sufficient to confer spermatid-specific expression on the hGH gene. We also show that 156 nucleotides of mP1 3'-untranslated sequence is sufficient to confer mP1-like translational regulation on the hGH mRNA. Interestingly, the subcellular localization of hGH was dependent on the time during spermiogenesis that it was made. Synthesis of hGH in early round spermatids resulted in localization in the acrosome, whereas synthesis in late elongating spermatids resulted in intracellular, but not acrosomal, localization.

Acrosome↗
PubMed1978

Shock of anaphylactoid type induced by protamine: a continuous cardiorespiratory record.

The intravenous administration of protamine to a patient after cardiac bypass caused a sudden increase in airway resistance and lung stiffness, and a severe drop in arterial blood pressure. The ventilatory obstruction reached its maximum after 30 s and had returned almost to normal in 3 min. Arterial hypotension with low pulse amplitude, decreased heart rate and ST depression in the ECG tracing developed 1.5 min after the respiratory symptoms. In spite of rapid blood transfusion, arterial pressure reached a low level after 5 min, but rose after isoprenaline administration. It is suggested that changes in the vascular and respiratory compartments occur in parallel with, but independently of, myocardial injury and depressed cardiac contractility.

Airway Resistance↗
PubMed1996

Expression of protamine P2 in the testis of the common marmoset and man visualized using non-radioactive in-situ hybridization.

Information on the organization of the spermatogenic cycle of the common marmoset (Callíthrix jacchus), a small New World primate, is limited to a single histological report on the differentiation of spermatids. In the present study we have used non-radioactive in-situ hybridization with a cRNA probe directed against marmoset protamine 2, on fixed sections of marmoset and human testis to elucidate the organization of mature germ cells within the seminiferous epithelium. Specificity of the probe was checked on Northern blots; mP2 hybridized exclusively to mRNA in samples extracted from marmoset and human testis. In sections from human and marmoset testis, positive staining for mRNA was confined to round and elongating spermatids and in the human was reduced in samples from patients with incomplete spermatogenesis. In the human, P2 mRNA was present in groups of cells consistent with the presence of more than one stage of the spermatogenic cycle in transverse sections of individual tubules. In the marmoset, P2-positive cells were detected as a continuous ring of staining in the majority of sections of tubules whilst in others only a group(s) of cells was positive. We conclude that the arrangement of the spermatogenic wave in this New World primate may be intermediate between that seen in rodents (segmental) and in the human (helical).

Amino Acid Sequence↗
PubMed1976

Protamines, histones and the genetic code. New evidence for code evaluations.

A new approach is presented to give evidence for the theories of Jukes and Crick (1-3) that at a more primitive stage the genetic code consisted of doublets separated by "comma-bases" rather than true triplets and that G and C or A and U are the exclusive bases used by the primordial code. This approach makes use of the conservation of the histone IV sequence over extremely long periods of time by comparing the amino acid composition of the average vertebrate protein with the one of histone IV, a reconstructed ancestral polypeptide and various nuclear proteins, homologous or otherwise related to it. All protamines studied and the majority of histones show deviations from the average vertebrate protein which are statistically highly significant if the amino acids sufficiently coded for by the first two bases are compared. A similar result is obtained for those amino acids which are sufficiently coded for by the first two bases of the codon and have codons composed of G and C only.

Amino Acid Sequence↗
PubMed1979

13C Nuclear magnetic resonance of protamines. The three main components of clupeine.

The three main components (called YI, YII and Z) of clupeine a protamine from herring have been isolated and characterized by 13C nuclear magnetic resonance. Resonance belonging to the many different amino acid carbon atoms are observable and assigned. The effect of urea on the clupeine fractions points to the molecules being essentially in extended form in 2H2O solutions. Unusual properties of clupeine fractions can be observed in the presence of phosphate. Two of the fractions, i.e. YI and Z, show that a partial folding occurs in some well-defined whereas fraction YII remains essentially unaltered.

Animals↗
PubMed1987

Isolation and characterization of a cDNA clone encoding testis protamine Z1 from the dog-fish Scylliorhinus caniculus.

A clone containing a 445-bp cDNA insert was isolated from a cDNA library synthesized from dog-fish testes mRNA. The nucleotide sequence was determined and corresponded to a 50-amino-acid protein. The known five-amino-acid N-terminal sequence corresponded exactly to our deduced amino acid sequence. After in vitro transcription of this cDNA using SP6 RNA polymerase, the translated polypeptide comigrated with the Z1 scylliorhinine marker. Analysis of the cDNA 3' flanking region of our Scylliorhinus protamine Z1 revealed an inverted repeat sequence, an ACAA motif and a CAGGAAAGA box known as regulatory signals for transcription termination in histone genes. In addition, sequences homologous to the simian virus (SV 40) and polyoma virus core enhancer elements were identified in the 5' and 3' flanking regions.

Amino Acid Sequence↗
PubMed1996

Dissociation of protamine-DNA complexes by Xenopus nucleoplasmin and minichromosome assembly in vitro.

Nucleoplasmin, an acidic thermostable protein abundant in the nucleus of Xenopus laevis oocytes, has been found to dissociate complexes of pUC19 DNA and protein phi 1, an intermediate protamine present in ripe sperm from the mollusc Mytilus edulis. Cruder preparations of nucleoplasmin, such as the amphibian oocyte S150 extract and its thermostable fraction, also dissociate the heterologous DNA-phi 1 complexes and, in addition, promote the assembly of plasmid DNA into a minichromosome displaying regular nucleosomal periodicity, as revealed by micrococcal nuclease digestion. In contrast, purified nucleoplasmin complemented with rat hepatocyte core histone octamers in the presence of DNA topoisomerase I, although capable of inducing nucleoprotein formation onto the complexed DNA, fails to position nucleosomes at the native spacings seen in chromatin in vivo. These data favour the existence of a general mechanism to bring about, in a concerted manner, removal of sperm-specific nuclear proteins and reconstitution of somatic chromatin following fertilization.

Animals↗
PubMed1994

In vitro and in vivo evaluation of protamine-heparin membrane for microencapsulation of rat Langerhans islets.

Rat pancreatic islets were microencapsulated with multilayer protamine-heparin (PH) membrane. Basal and stimulatory insulin secretion of microencapsulated islets was similar to the controlled free islets in vitro. During the long-term culture (up to 2 weeks) mean insulin release of encapsulated islets did not significantly differ from the mean of free ones (the ratio of mentioned means was 54-167%). Empty PH microcapsules transplanted into Wistar rats intraperitoneally and under the kidney capsule were generally harmless up to 4 months. In only a few cases traces of fibrotic tissue around capsules entrapped in the omentum were found. No damage of microcapsules structure was observed. The worst results were obtained in the instance of retroperitoneal transplantation. We conclude, therefore, that PH membrane was proved to be highly biocompatible, nontoxic for islets, and did not impair viability and glucose-dependent insulin secretion of Langerhans islets in in vitro culture.

Animals↗
PubMed2004

A K+ yptake protein, TrkA, is required for serum, protamine, and polymyxin B resistance in Vibrio vulnificus.

Vibrio vulnificus, a highly virulent marine bacterium, is the causative agent of both serious wound infections and fatal septicemia in many areas of the world. To identify the genes required for resistance to human serum, we constructed a library of transposon mutants of V. vulnificus and screened them for hypersensitivity to human serum. Here we report that one of the isolated serum-susceptible mutants had a mutation in an open reading frame identified as trkA, a gene encoding an amino acid sequence showing high identity to that of TrkA of Vibrio alginolyticus, a protein required for the uptake of potassium. A trkA isogenic mutant was constructed via insertional inactivation, and it was significantly more easily killed by human serum, protamine, or polymyxin B than was the wild type. At K+ concentrations of 1 to 20 mM, this isogenic mutant showed attenuated growth compared to the wild-type strain. In addition, infection experiments demonstrated virulence attenuation when this mutant was administered intraperitoneally or subcutaneously to both normal and iron-treated mice, indicating that TrkA may modulate the transport of potassium and resistance to host innate defenses and that it is important for virulence in mice.

Animals↗
PubMed2001

MSY2 and MSY4 bind a conserved sequence in the 3' untranslated region of protamine 1 mRNA in vitro and in vivo.

Y-box proteins are major constituents of ribonucleoprotein particles (RNPs) which contain translationally silent mRNAs in gametic cells. We have recently shown that a sequence-specific RNA binding activity present in spermatogenic cells contains the two Y-box proteins MSY2 and MSY4. We show here that MSY2 and MSY4 bind a sequence, 5'-UCCAUCA-3', present in the 3' untranslated region of the translationally repressed protamine 1 (Prm1) mRNA. Using pre- and post-RNase T1-digested substrate RNAs, it was determined that MSY2 and MSY4 can bind an RNA of eight nucleotides containing the MSY2 and MSY4 binding site. Single nucleotide mutations in the sequence eliminated the binding of MSY2 and MSY4 in an electrophoretic mobility shift assay, and the resulting mutants failed to compete for binding in a competition assay. A consensus site of U(AC)C(A)CAU(C)CA(CU) (subscripts indicate nucleotides which do not disrupt YRS binding by MSY2 and MSY4), denoted the Y-box recognition site (YRS), was defined from this mutational analysis. These mutations in the YRS were further characterized in vivo using a novel application of the yeast three-hybrid system. Experiments with transgenic mice show that disruption of the YRS in vivo relieves Prm1-like repression of a reporter gene. The conservation of the RNA binding motifs among Y-box protein family members raises the possibility that other Y-box proteins may have previously unrecognized sequence-specific RNA binding activities.

3' Untranslated Regions↗
PubMed1985

Complement activation and anaphylactoid response to protamine in a child after cardiopulmonary bypass.

A 2 1/2 year old boy had a sudden, severe, and unexpected anaphylactoid reaction after an otherwise uncomplicated repair of a partial atrioventricular septal defect. The reaction, comprising haemorrhagic pulmonary oedema and peripheral circulatory collapse, followed neutralisation of heparin by protamine. Measurements of serum complement (C3 and C4) concentrations suggested that a pronounced consumption of complement occurred during the adverse response.

Anaphylaxis↗
PubMed1976

Improved antibody detection by the use of range expansion and longer filter wavelength in a low ionic strength-protamine sulphate Auto-Analyzer system.

Range expansion, achieved by insertion of a variable resistance between the colorimeter and the recorder together with the use of 550 nm colorimeter filters, has resulted in markedly improved sensitivity for antibody detection, and improved sample identification, in a low ionic strength-protamine sulphate (LISPS) system. Range expansion also permits a lower concentration of red cells to be used, thus economizing on fully typed cells. Glycerol stored frozen cells were found to be only slightly less sensitive than fresh cells in this system.

Antibodies↗
PubMed1980

Ineffectiveness of protamine zinc somatostatin as a long-acting inhibitor of insulin and growth hormone secretion.

The present studies examined the duration of inhibitory action of a preparation of cyclic somatostatin (SRIF) in suspension with protamine zinc (PZ) on (1) physiologic growth hormone (GH) and immunoreactive insulin (IRI) secretion during feeding in the rat and (2) plasma IRI levels in a 10-year-old boy with idiopathic hyperinsulinemic hypoglycemia. Chronically cannulated adult male rats were administered 250 microgram PZ-SRIF subcutaneously twice daily at 12-h intervals for 7 days. Control animals received the PZ vehicle on the same schedule. On the test day, blood samples were obtained every 15 min for periods of 6 h following a single PZ-SRIF injection 1.5 h prior to sampling. Prominent GH secretory bursts were still evident in all PZ-SRIF-treated rats and these pulses occurred at the predictable time in relation to the light-dark cycle. Plasma IRI levels were typically elevated in response to feeding and no significant differences were observed in the mean 6-h GH, IRI, and glucose levels of PZ-SRIF-treated rats when compared with PZ-treated controls. In the boy with idiopathic hyperinsulinemic hypoglycemia, subcutaneous injection of 200 microgram PZ-SRIF depressed plasma IRI levels for only 30 min. These results suggest that PZ is not the agent of choice for significant prolongation of the inhibitory action of SRIF on IRI and GH secretion.

Animals↗
PubMed1992

Protamine interaction with the epithelial cell surface.

We have previously reported that exposing cultured Madin Darby canine kidney (MDCK) cells to the polycation protamine (PRO) results in increased short-circuit current and decreased barrier integrity as measured by mannitol permeability and transepithelial electrical resistance. To further investigate the interaction of PRO with the surface of epithelial cells, we labeled PRO with [14C] with use of reductive alkylation. [14C]PRO bound to the cells in a biphasic pattern. Approximately 10% of the [14C]PRO was bound to the cells in the first 5 min, followed by an additional 10% that was bound over the next 25 min. No additional [14C]PRO bound to the cells after the initial 30 min. Binding of [14C]PRO was inhibited by "cold" PRO, which suggested specificity. Binding was also inhibited by polyanions, serum, and albumin, agents previously found to protect MDCK cells from PRO-induced injury. The binding of PRO to MDCK cells was not inhibited by incubation of the MDCK cells with neuraminidase, to remove surface sialic acid residues, or with heparinase, to remove surface heparan sulfate, even though metabolic labeling experiments demonstrated that neuraminidase decreased cell sialic acid and heparinase decreased cell heparan sulfate. Neuraminidase and heparinase offered no protection from PRO injury and had no effect themselves on mannitol permeability. Incubation of the cells with trypsin, however, blunted both the binding of PRO to the cells and the increase in mannitol permeability after exposure of the cells to PRO.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗