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S Kure

Publications and source records attributed to S Kure.

At least 73 records · Page 4Linked to original sources
PubMed1991

The glycine cleavage system. Molecular cloning of the chicken and human glycine decarboxylase cDNAs and some characteristics involved in the deduced protein structures.

A cDNA encoding chicken glycine decarboxylase (pCP15b) was isolated using an antibody specific to this protein. Additional cDNAs were cloned with the aid of the genomic fragments obtained by using the pCP15b cDNA probe. No initiator methionine codon is found in the currently elucidated cDNA sequence, and an ATG codon in an exon is assigned to this role. The precursor glycine decarboxylase deduced from the 3514-base pair nucleotide sequence is comprised of 1,004 amino acids (Mr = 111,848). The 1,020 amino acid residues are encoded for the precursor form of human glycine decarboxylase (Mr = 112,869) in the 3,783-base long cDNA sequence of two 1.9-kilobase pair cDNAs with a pentanucleotide overlap. The pyridoxal phosphate binding site lysine and a glycine-rich region, which is suggested to be responsible for the attachment of the phosphate moiety of pyridoxal phosphate, are found in close proximity in both the chicken and human enzymes. This region essential for the enzyme action is suggested to be embedded in a segment rich in beta-turns and random coils and is surrounded by conserved and repetitive amino acid sequences. It is suggested that these structures are involved in the organization of the active site of glycine decarboxylase.

Amino Acid Oxidoreductases↗
PubMed1991

The glycine cleavage system. The coupled expression of the glycine decarboxylase gene and the H-protein gene in the chicken.

Regulation of the transcription of the glycine decarboxylase gene and the H-protein gene was examined in chicken. Northern analysis suggested and run-off transcription confirmed that the glycine decarboxylase gene transcription is exclusively tissue-specific and takes place at different efficiencies in liver, kidney, and brain which are the chicken tissues exhibiting the glycine cleavage activity. No evidence for the glycine decarboxylase gene transcription was obtained in heart, spleen, and skeletal muscle. Basal and tissue-specific transcription of the H-protein gene can be distinguished. The tissue-specific transcription coordinates with transcription of the glycine decarboxylase gene in active tissues, while low abundance H-protein and its mRNA, products of the basal transcription, exist in inactive tissues together with small amounts of T-protein. Apparently, T-protein is synthesized by a process similar to that for H-protein. Glycine decarboxylase mRNA levels show a linear relationship with H-protein mRNA levels and with specific activities of the glycine cleavage reaction in active tissues. Tissue-specific distribution of the glycine cleavage activity is primarily determined by the expression of the glycine decarboxylase gene. The coordinate and tissue-specific transcription of the genes for the constituent proteins plays a key role in determining the magnitude of the glycine cleavage activity in chicken tissues and, thereby, the tissue-specificity of glycine metabolism.

Amino Acid Oxidoreductases↗
PubMed1991

Structural and expression analyses of normal and mutant mRNA encoding glycine decarboxylase: three-base deletion in mRNA causes nonketotic hyperglycinemia.

Full-length cDNA clone encoding human glycine decarboxylase (P-protein) was isolated from the human placental lambda gt11 expression library using specific antibodies. This clone was 3,705 bp in length and encoded 1,020 amino acids. We studied the structure of the mutant P-protein mRNA expressed in the liver of a patient with nonketotic hyperglycinemia (NKH) deficient of P-protein. A three-base deletion, which resulted in deletion of Phe756, was found. Cos7 cells in which normal P-protein cDNA was expressed presented an activity of 6.9 +/- 0.41 nmole/milligram of protein/hour, which was almost equivalent to that of human liver. In contrast, Cos7 cells in which the mutant cDNA was expressed showed no activity, indicating that the three-base deletion could cause NKH.

Amino Acid Metabolism, Inborn Errors↗
PubMed1990

One of the two genomic copies of the glycine decarboxylase cDNA has been deleted at a 5' region in a patient with nonketotic hyperglycinemia.

One of eight patients with nonketotic hyperglycinemia resulted by the lesion in glycine decarboxylase showed the deletion of 0.6-kb SacI and 1.5-kb PstI fragments identified by the cDNA for this protein. A genomic clone, lambda HGDG10, encodes a 5' region of this cDNA in an organized structure and can produce these two fragments. The other clone, lambda HGDG8, carries a processed gene. Southern analysis using a limited segment of this cDNA demonstrated that the 1.7-kb and 1.5-kb PstI fragments predicted from its recognition sites in both genomic clones occur actually in the human genome, indicating that at least two copies of glycine decarboxylase cDNA exist in the haploid genome, and the patient has the glycine decarboxylase gene deleted at a 5' region.

Amino Acid Oxidoreductases↗
PubMed1988

Structure, turnover, and heme-mediated suppression of the level of mRNA encoding rat liver delta-aminolevulinate synthase.

lambda gt11 cDNA libraries were constructed with poly(A)+ RNA preparations from both porphyric chicken and rat livers. A cDNA which encodes chicken hepatic delta-aminolevulinate synthase was cloned by screening with an anti-chicken liver delta-aminolevulinate synthase antibody. Using this cDNA as a probe, cDNAs encoding the entire protein coding sequence of rat hepatic delta-aminolevulinate synthase were then cloned. The complete nucleotide sequences of the cDNAs have been determined. The result predicts that the rat hepatic pre-delta-aminolevulinate synthase comprises 642 amino acids. We measured the half-life of the hepatic delta-aminolevulinate synthase mRNA by RNA blot hybridization analysis using allylisopropylacetamide-induced porphyric rats as an experimental model and the rat cDNA as a hybridization probe. The half-life of the mRNA determined by the injection of alpha-amanitin is as short as 20 min. This value is significantly shorter than the estimated half-lives of most other mRNAs in the differentiated tissues of animals. The effect of hemin administration on the level of hepatic delta-amino-levulinate synthase mRNA was also examined. The half-disappearance time of the mRNA after the hemin administration was essentially the same as that determined by alpha-amanitin or actinomycin D, and no additive effect was observed between alpha-amanitin and hemin on the half-life determination. The results provide convincing evidence that heme inhibits the transcription of delta-aminolevulinate synthase mRNA.

5-Aminolevulinate Synthetase↗
PubMed1988

The impaired expression of glycine decarboxylase in patients with hyperglycinemias.

Glycine decarboxylase, a constituent of the glycine cleavage system, in patients with either nonketotic or ketotic hyperglycinemia (NKH and KH) was examined using an anti-chicken glycine decarboxylase antibody. Patients with NKH who have lesion in glycine decarboxylase are differentiated by its expressed level in the liver. One group is cases of the neonatal onset type who have neither activity of the enzyme nor protein reactive to the antibody. The other is a case of the late onset type who shows low but detectable activity of the enzyme and the desirable amount of the immunoreactive material. In the liver of a patient with KH not showing the appreciable activity of H-protein, ubiquitous amount of protein reactive to anti-H-protein IgG is detected and amount of glycine decarboxylase has also been lowered. It is suggested that several mechanisms may be involved in determining the expressed level of glycine decarboxylase in patients with hyperglycinemias.

Adult↗
PubMed1988

Cloning of cDNA encoding human H-protein, a constituent of the glycine cleavage system.

A cDNA that encodes human H-protein, a constituent protein of the glycine cleavage system, was cloned with anti-rat H-protein antibody as a probe from a human liver cDNA library constructed with an expression vector, lambda gt11. The longest size of cDNA of the isolated clones was about 750 base long (lambda HH15B9). On the other hand, we determined the primary structure of human H-protein from the amino terminal Ser by the 12th Val, including a hexapeptide, -Glu-Lys-His-Glu-Trp-Val-. In addition to the finding that most cDNA inserts cloned hybridized with the synthetic DNA probe composed of the possible sequences for the hexapeptide, we confirmed that lambda HH15B9 encodes the partial primary structure of H-protein in an open reading frame.

Amino Acid Oxidoreductases↗
PubMed1987

Metastatic potential of murine B16 melanoma correlates with reduced surface heparan sulfate glycosaminoglycan.

We studied the relationship between the metastatic potential of murine B16 melanoma cells and their surface expression of heparan sulfate glycosaminoglycan (HS-GAG) by using HepSS-1, a monoclonal antibody specific to HS-GAG. Firstly, among five B16 sublines, those capable of developing lung colonies with high efficiencies, such as B16-F10, had relatively low levels of surface HS-GAG. Secondly, a subline freshly prepared from metastatic lung colonies (F1) displayed a level of surface HS-GAG lower than that of injected B16 cells. Thirdly, in vitro selection of B16 cells with low surface HS-GAG by repeated HepSS-1 staining and cell-sorting resulted in cells with a higher metastatic efficiency than that of the original B16 cells. Collectively, B16 melanoma cells with high metastatic activities seem to have low surface HS-GAG. We also found that there was a positive correlation between the surface level of HS-GAG and the susceptibility to natural killer cells in eight B16 sublines.

Animals↗
PubMed1986

A syngeneic monoclonal antibody to murine Meth-A sarcoma (HepSS-1) recognizes heparan sulfate glycosaminoglycan (HS-GAG): cell density and transformation dependent alteration in cell surface HS-GAG defined by HepSS-1.

We have isolated a syngeneic monoclonal antibody (HepSS-1) reactive to a murine methylcholanthrene-induced fibrosarcoma, Meth-A. HepSS-1 also bound to a wide variety of established and fresh normal cells derived from not only mice but also other species such as human, monkey, rat, hamster, and chicken. Immunoprecipitation of surface iodinated Meth-A cell extract with HepSS-1, as well as Sepharose 4B gel chromatography of Meth-A cell extract and detection of antigens recognized by HepSS-1 by a sandwich-type radioimmunoassay revealed that the HepSS-1 antigens were composed of several molecular species, with one as large as approximately 10(6) daltons. The following evidence indicates that HepSS-1 specifically recognizes an epitope present in heparan sulfate glycosaminoglycan (HS-GAG). First, treatment of Meth-A cells with heparitinase or heparinase, but not with chondroitinase ABC or hyaluronidase, resulted in the loss of HepSS-1 binding. Second, HS-GAG but not seven other types of GAG (hyaluronic acid, heparin, chondroitin, chondroitin 4-sulfate, chondroitin 6-sulfate, dermatan sulfate, and keratan sulfate) inhibited HepSS-1 binding to Meth-A cells. Third, HepSS-1 bound with HS-GAG but not with the seven other types of GAG. From the binding analysis of HepSS-1 to various modified HS-GAG and whale omega-heparin, it is additionally suggested that HepSS-1 recognizes an epitope closely related to O-sulfated and N-acetylated glucosamine. We found that NIH 3T3 cells expressed more HepSS-1 epitopes at a low cell density than at confluency and in G2 + M than in G1, whereas NIH 3T3 cells transformed with Kirsten-ras oncogene or SV-40 expressed high levels of HepSS-1 epitopes and ceased to show the density-dependent change in the amount of HepSS-1 epitopes. These observations were also reproduced by using NIH 3T3 cells transformed with a temperature sensitive Kirsten murine sarcoma virus maintained at permissive and non-permissive temperatures. Thus HepSS-1 is a first monoclonal antibody to HS-GAG and seems to be useful to elucidate changes in cell surface HS-GAG in normal cell growth and cell transformation.

Animals↗
PubMed1986

Inhibition of Epstein-Barr virus infection in vitro by recombinant human interferons alpha and gamma.

The inhibitory effects of pure recombinant human interferons alpha A and gamma (reIFN-alpha A and -gamma) on Epstein-Barr virus (EBV) infection of a human EBV-negative B cell line, BJAB, and of normal adult B lymphocytes were studied. With pretreatment for 24 h, both types of reIFNs were effective in suppressing the production of EBV specific nuclear antigen (EBNA-1) in BJAB cells 24 h after EBV-infection, as determined by the immunoblotting technique. ReIFN-alpha A was, however, a much more potent inhibitor than reIFN-gamma. With treatment starting 1 h after EBV infection, both types of reIFNs were less effective in the suppression of EBNA production. Neither of the reIFNs showed any inhibitory effect on EBNA production in the latently EBV-infected cell lines, Raji and Daudi. These results suggest that reIFNs act in the early phase of EBV infection. Both types of reIFNs were also effective in inhibiting EBV infection of normal adult B lymphocytes as demonstrated by a reduction both in [3H]thymidine incorporation 6 days after EBV infection and in the total number of proliferating cells 21 days after EBV infection. Again, reIFN-alpha A showed a greater inhibitory effect than reIFN-gamma. We also showed that in BJAB cells, reIFN-alpha A strongly induced (2'-5')oligoadenylate synthetase activity, whereas reIFN-gamma increased the surface expression of HLA class I antigens.

2',5'-Oligoadenylate Synthetase↗
PubMed1982

[Not Available].

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Expeditions↗