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O Hatase

Publications and source records attributed to O Hatase.

At least 19 recordsLinked to original sources
PubMed1992

The evidence for post-meiotic expression of a testis-specific isoform of a regulatory subunit of calcineurin using a monoclonal antibody.

The expression of a regulatory subunit of calcineurin (CaN beta) during rat spermatogenesis was examined in rat testes using a monoclonal antibody Va1. Results showed that a testis-specific isoform of CaN beta was expressed only 3 weeks after birth, when meiosis begins, and increased in amount depending on the maturation of spermatogenesis. The matured sperm, which consists of only post-meiotic cells, is most likely to have only the testis-specific isoform of CaN beta. The brain type isoform of CaN beta was not detected in rat sperm. Immunoblot analysis of testes from different rodent species by a monoclonal antibody Va1 showed that all rodent species examined had their own homologues corresponding to a testis-specific isoform of CaN beta in rats, although they showed distinctively different molecular weights on SDS-PAGE compared to the testis-specific isoform in rats. Each homologue was shown to be specifically expressed in post-meiotic phase of spermatogenesis, as was seen in rats.

Aging↗
PubMed1992

Identification of a src family protein specifically expressed in rat astrocytes by immunohistochemistry and double immunofluorescent study.

Identification of a src-related tyrosine kinase and its regional and cellular distributions were studied in rat brain. The study was performed using a specific antibody raised against a synthetic peptide corresponding to the conserved autophosphorylation site of src-family tyrosine kinases. The antibody (alpha-src antibody) recognized a 43 kDa polypeptide in plasma membrane enriched fraction. The immunohistochemical data revealed that the polypeptide is localized in astrocytes of corpus callosum and fimbria hippocampus. The presence of this src-related protein in astrocytes suggests that it may have some control in their proliferation and differentiation.

Animals↗
PubMed1992

A synthetic peptide derived from p34cdc2 is a specific and efficient substrate of src-family tyrosine kinases.

A peptide derived from p34cdc2, cdc2(6-20)NH2 with the amino acid sequence of KVEKIGEGTYGVVYK-amide, was found to be a specific and efficient substrate for a pp60c-src-related protein tyrosine kinase from bovine spleen (STK). Glu-12 and Thr-14 were identified to be substrate specificity determinants in this peptide (Cheng, H.-C., Litwin, C. M. E., Hwang, D. M., and Wang, J. H. (1991) J. Biol. Chem. 266, 17919-17925). In this study, we demonstrated the presence of cdc2(6-20)NH2 peptide tyrosine kinase activity in the membrane fractions of bovine brain, spleen, thymus, lung, liver, and kidney. Hydroxylapatite column chromatography of thymus membrane extract revealed four protein tyrosine kinases, TK-I, TK-II, TK-III, and TK-IV, with different relative activities toward cdc2(6-20)NH2 and a general tyrosine kinase substrate, poly(Glu/Tyr). Only TK-I and TK-II showed significant activity toward cdc2(6-20)NH2, they were suggested as belonging to the src-family by virtue of their cross-reactivity with an antibody against a synthetic peptide corresponding to a conserved sequence of src-family kinases. Further immunological characterization using antibodies specific to individual src-related protein tyrosine kinases suggested that TK-I, TK-II, and STK are bovine homologs of p56lck, p55fyn, and p56lyn, respectively. Substrate specificity and kinetic characterization of src-family tyrosine kinases including human platelet pp60c-src, bovine p56lyn, p56lck, and p55fyn, as well as several non-src-related tyrosine kinases including epidermal growth factor receptor, p43v-abl, TK-III, and TK-IV showed that all the src-family tyrosine kinases but none of the other kinases displayed efficient cdc2(6-20)NH2 phosphorylation. In all cases, the high efficiency of cdc2(6-20)NH2 peptide phosphorylation could be markedly attenuated when Glu-12 and Thr-14 of the peptide were substituted, respectively, by valine and serine.

Amino Acid Sequence↗
PubMed1992

In vivo microdialysis of amino acid neurotransmitters in the hippocampus in amygdaloid kindled rat.

Extracellular concentrations of gamma-aminobutyric acid (GABA), glutamate (Glu) and aspartate (Asp) were determined by microdialysis in rat hippocampus during various amygdaloid kindled stages. The values of GABA and Glu were increased 3-4 times in C2-C3 stages in comparison with the values in control animals. After reaching the C5 stages, these values were increased 3-7 times. However, the concentration of Asp decreased depending on the kindling stage, reaching the lowest value of 33% in comparison with the normal value. The observed changes may be related to kindling induced seizures.

Amygdala↗
PubMed1992

Identification of testis specific calcineurin beta subunit isoform by a monoclonal antibody and detection of a specific six amino acid sequence.

Two isoforms of calcineurin beta subunit(beta 1 and beta 2) were identified in rat testis by a monoclonal antibody Va1. Both beta 1 and beta 2 were recovered in calmodulin binding protein fraction and showed calcium shift on SDS-polyacrylamide gel electrophoresis which is the specific character for EF-hand calcium binding protein. beta 2 showed same apparent molecular weight on SDS-PAGE as that of brain calcineurin beta and was found in wide variety of tissues. beta 1 was shown to have six amino acid polypepeptide sequence and it showed higher molecular weight than brain beta and was specific for testis.

Amino Acid Sequence↗
PubMed1992

Familial increase in plasma glutamic acid in epilepsy.

Plasma levels of glutamic acid and leukocyte glutamate dehydrogenase (GDH) activity were determined in patients with primary generalized epilepsy, patients with partial epilepsy and in the first-degree relatives of these subjects. The results show a significant increase in plasma glutamic acid in both groups of patients and their relatives compared to non-epileptic controls. The leukocyte GDH activity in the patients and the relatives was not different from controls. The data support a genetic basis for plasma glutamic acid increase in both primary generalized and partial epilepsy and are compatible with the multifactorial mode of inheritance of these disorders. This is the first study showing a familial plasma glutamic acid increase in epilepsy in a Japanese population.

Adolescent↗
PubMed1992

Plasma urea and ammonia in epileptic patients and their relatives.

The plasma levels of urea and ammonia were examined in patients with primary generalized epilepsy, patients with partial epilepsy and in the first-degree relatives of these subjects. The results show a significant decrease in plasma urea in both groups of patients and their first-degree relatives as compared to the non-epileptic controls. The plasma ammonia concentrations were significantly higher in both groups of patients and in the relatives of generalized epilepsy patients as compared to the controls. The observed changes in plasma urea and ammonia were found not to be due to the effect of anticonvulsant drugs. The data suggest that a metabolic defect in urea synthesis may constitute one of the genetic components in the multifactorial etiologies of primary generalized and partial epilepsies.

Adolescent↗
PubMed1991

Isolation and sequence of rat testis cDNA for a calcium binding polypeptide similar to the regulatory subunit of calcineurin.

We have cloned and sequenced rat testis cDNAs coding for a calcium binding polypeptide similar to calcineurin beta subunit, the Ca(2+)-binding subunit of the Ca2+/calmodulin stimulated protein phosphatase. Rat testis cDNA library was screened with a monoclonal antibody Va1 raised against bovine brain calcineurin beta subunit. The deduced amino acid sequence is similar to that of human brain calcineurin beta subunit with respect to containing four putative calcium binding sites. However, distinct differences were found: 1) The cloned cDNA had six amino acids polypeptide tail at carboxy-terminal which is absent in human brain calcineurin beta subunit. This amino acids tail makes the carboxy-terminal highly hydrophilic in contrast to the human brain beta subunit which is hydrophobic at carboxy-terminal; 2) eleven amino acids at the N terminal of the cloned cDNA were completely different from the corresponding region of the brain calcineurin beta subunit.

Amino Acid Sequence↗
PubMed1991

Increase of extracellular insulin-like growth factor I (IGF-I) concentration following electrolytical lesion in rat hippocampus.

The change of extracellular insulin-like growth factor I (IGF-I) level following electrolytical lesion in rat hippocampus was studied by intracerebral microdialysis technique. The microdialysis probes were inserted into the lesioned and normal side of hippocampus on the day and each week after making the lesion for a period of four weeks. The content of IGF-I in the dialysis perfusate was measured by a radioimmunoassay. One week after surgery, IGF-I level (mean +/- S.E.M.) increased from 235.6 +/- 25.4 pg/100 microliters perfusate (day 0) to 305.5 +/- 15.6 pg/100 microliters perfusate (day 7), and then decreased gradually. This suggests that there is accumulation or increase in secretion of IGF-I at the lesioned site, and that IGF-I might have an important role in vivo in the brain tissue recovery from damage.

Animals↗
PubMed1991

Identification of two calcineurin alpha isoforms in bovine brain by two different monoclonal antibodies.

Calcineurin (calcium- and calmodulin-stimulated phosphatase) alpha subunit purified from bovine brain was found to be composed of two polypeptides, 61 KDa (alpha 1) and 59 KDa (alpha 2). The two peptides were separated and extracted from polyacrylamide gel. The immuno-peptide mapping of the purified peptides by partial proteolysis showed that the 59-KDa polypeptide was not a degradative product of the 61-KDa polypeptide. The interaction of the enzyme with two monoclonal antibodies, Vj6 and Vd3, raised against bovine brain calcineurin revealed that the 61-KDa polypeptide was recognized by both Vj6 and Vd3, whereas the 59-KDa one was recognized only by Vj6. These results indicate that there are at least two isoforms of calcineurin alpha subunits in bovine brain.

Animals↗
PubMed1991

Mechanism of transient increase in intracellular concentration of free calcium ions in HL-60 cell differentiation induced by vitamin D3 and phorbol ester.

A promyelocytic leukemia cell line, HL-60, was induced to differentiate into monocyte-macrophage lineage cells by treatment with active vitamin D3 and phorbol esters, and into granulocyte lineage ones by retinoic acid and dimethylsulfoxide. The changes in intracellular concentration of free calcium ions ([Ca2+]i) were measured and analyzed by calcium-imaging analysis with Fura 2-AM. A significant and transient increase in [Ca2+]i was observed in active vitamin D3 and phorbol ester systems; however, no change was detected with retinoic acid and dimethylsulfoxide. This increase was due to the influx of calcium ions from outside of the cells, and L-type calcium channels were shown to mainly contribute to this influx. Protein kinase C was also shown to be involved in the increase in [Ca2+]i.

Calcitriol↗
PubMed1990

Insulin-like growth factor I (IGF-I) distribution in the tissue and extracellular compartment in different regions of rat brain.

The regional distribution of insulin-like growth factor I (IGF-I) was examined in the tissue and extracellular compartment of rat brain. The tissue content of IGF-I was the highest in the pituitary gland, followed by the olfactory bulb, upper brainstem, cerebellum, striatum, hippocampus, lower brainstem, and cerebral cortex. The extracellular concentration was studied by intracerebral microdialysis technique, and the highest content was found in the hippocampus, followed by the olfactory bulb, hypothalamus, cerebellum, striatum, and cerebral cortex. The tissue and extracellular contents were significantly correlated in the olfactory bulb, hypothalamus, cerebellum, striatum, and cerebral cortex. IGF-I might act by paracrine and/or autocrine regulatory mechanisms in these regions.

Animals↗
PubMed1990

Induction of differentiation of HL-60 cells by protein kinase C inhibitor, K252a.

To clarify the role of protein kinase C and protein kinase A in cell proliferation and differentiation, the effects of K252a and its derivatives (K252b, KT5720), which have different inhibitory activity to these protein kinases, on the proliferation and differentiation of HL-60 cells were investigated. The proliferation and DNA synthesis of the HL-60 cells were inhibited by K252a in a dose dependent manner. However, K252b and KT5720 which are more specific inhibitors of protein kinase C or protein kinase A, respectively, had no observable effect on cell proliferation. K252a (40nM) enhanced the differentiation of HL-60 cells induced by 1,25(OH)2D3, retinoic acid and DMSO. K252b and KT5720 did not affect 1,25(OH)2D3-induced differentiation. K252a significantly inhibited the differentiation induced by PMA. These results demonstrate that K252a but not its derivatives can function as an antitumor drug and enhancer of the differentiation induced by various inducers.

Carbazoles↗
PubMed1990

Inhibition of platelet aggregation by S-(1,2-dicarboxyethyl)glutathione, intrinsic tripeptide in liver, heart, and lens.

S-(1,2-Dicarboxyethyl)glutathione (DCE-GS) found in animal tissues or baker's yeast showed strong inhibitory effects on blood coagulation and platelet aggregation. The inhibitory effect of blood coagulation was almost the same as those of EDTA, oxalate, and citrate. DCE-GS did not show chelating activity. As for ADP- or thrombin-induced platelet aggregations, DCE-GS exerted a potent effect on the secondary aggregation, while it was less active in the primary aggregation. DCE-GS gave a distinct lag period in the time course of the secondary aggregation induced by collagen and inhibited most strongly the aggregation induced by arachidonic acid compared with those elicited by ADP, thrombin, and collagen. The peptide, however, did not inhibit the platelet aggregation induced by 12-O-tetradecanoylphorbol-13-acetate. Although both DCE-GS and EDTA inhibited the platelet aggregation which was triggered by ADP, their inhibitory manners were entirely different.

Adenosine Diphosphate↗
PubMed1990

In vivo analysis of extracellular proteins in rat brains with a newly developed intracerebral microdialysis probe.

Peptides and proteins in the extracellular space in the central nervous system were investigated in vivo using an intracerebral microdialysis probe. The molecular cut-off of the hollow fiber which was used for the probe was approximately 100 kDa. We examined recovery rates of several compounds in vitro. The recovery rates of proteins and peptides were between 7-28%, with the exceptions of substance P and insulin-like growth factor I. The recovery rates of monoamines and their metabolites were 22-40%. In in vivo studies, two major proteins with apparent molecular weights of 62 kDa and 12 kDa, and several minor proteins (28 kDa, 43 kDa, 52 kDa and 70 kDa) were detected by SDS-polyacrylamide gel electrophoresis in the dialysate from a probe implanted in the striatum of anesthetized rats. These results suggest that the newly developed, intracerebral microdialysis probe might be useful for investigating the dynamic changes of peptides and proteins in the central nervous system.

Animals↗
PubMed1990

Purification and immunohistochemical study of actin in mitochondrial matrix.

Actin was purified to apparent homogeneity from the matrix of ultra-pure mitochondria of rat livers by DNase-I affinity chromatography and HPLC gel filtration. The mitochondrial actin was immunologically identified by an anti-actin antibody, and its apparent molecular weight was 43 KDa, as determined by SDS-polyacrylamide gel electrophoresis. The immunohistochemical study revealed the localization of the mitochondrial actin in the matrix space and on the internal surface of inner membrane. The actin fraction eluted from a DNase-I column by KCl-EGTA solution underwent polymerization and bundling in vitro.

Actins↗