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Kazunori Shibuya

Publications and source records attributed to Kazunori Shibuya.

9 recordsLinked to original sources
PubMed2005

Identification of a novel zinc finger protein gene (ZNF298) in the GAP2 of human chromosome 21q.

We have isolated a novel zinc finger protein gene, designated ZNF298, as a candidate gene for a particular phenotype of Down syndrome or bipolar affective disorder (BPAD) which maps to human chromosome 21q22.3. ZNF298 gene consists of 25 exons spanning approximately 80kb in a direction from the telomere to centromere. There are four kinds of transcripts that harbor three types of 3' UTR. These four transcripts (ZNF298a, ZNF298b, ZNF298c, and ZNF298d) contain putative open reading frames encoding 1178, 1198, 555, and 515 amino acids, respectively. ZNF298 gene was ubiquitously expressed in various tissues at very low level. The protein motif analysis revealed that ZNF298 proteins contain a SET [Su(var)3-9, Enhancer-of-zeste, Trithorax] domain, multiple C2H2-type zinc finger (ZnF_C2H2) domains, several nuclear localization signals (NLSs), and PEST sequences. Nuclear localization of ZNF298 protein was confirmed by transfection of expression vector of GFP-tagged protein into two human cell lines. Interestingly, this gene crosses over a clone gap (GAP2) remaining in the band 21q22.3. We obtained the DNA fragments corresponding to GAP2 using ZNF298 cDNA sequence as anchor primers for PCR and determined its genomic DNA sequence.

Amino Acid Sequence↗
PubMed2004

Initial characterization of an uromodulin-like 1 gene on human chromosome 21q22.3.

We have isolated a novel gene, designated UMODL1, similar to uromodulin (UMOD)/Tamm-Horsfall glycoprotein, on human chromosome 21q22.3. Uromodulin like-1 (UMODL1) consists of 22 exons and spans approximately 80 kb in a direction from centromere to telomere. Two major transcripts produced by alternative splicing have been identified. These transcripts contain open reading frames of 4125 and 3741 bp encoding proteins of 1374 and 1246 amino acids, respectively. Expression of UMODL1 mRNA was detected only in 14 human tissues, e.g., kidney, testis, and fetal thymus at low level. Interestingly, two gene products (UMODL1L and UMODL1S) contain multiple domains including whey acidic protein, sea urchin sperm protein, enterokinase, and agrin, zona pellucida domain, and so on. Both proteins seemed to localize in cytoplasm, but UMODL1 is likely to be ubiquitinated and rapidly degraded in HEK293 cells. This gene may be a potent candidate for Down syndrome or bipolar affective disorder.

Alternative Splicing↗
PubMed2004

Identification of two novel clusters of ultrahigh-sulfur keratin-associated protein genes on human chromosome 11.

We analyzed two novel clusters of keratin-associated protein (KAP) genes on human chromosome 11 (11p15.5 and 11q13.5) in which we identified two known human KRTAP5 genes, KerA (=KRN1) and KerB, and nine novel KRTAP5 family genes. RT-PCR analysis of these KAP genes showed preferential expression in human hair root, suggesting these gene products are required for hair formation. Based on the deduced amino acid sequences, all these KAP proteins were classified into an ultrahigh-sulfur (UHS) type KAP with high cysteine content (> 30 mol%). These KAPs also showed high glycine and serine contents (average 24.30 and 21.13 mol%, respectively), distinguishing from other UHS/HS KAP families located on human chromosomes 17 and 21. Dot-matrix analysis revealed a significant similarity between these two KAP gene clusters. We postulated a mechanism by which these two KAP gene clusters are generated via genomic duplication of a primordial gene cluster followed by genetic modification during evolution.

Amino Acid Sequence↗
PubMed2004

Comparative genomics of the keratin-associated protein (KAP) gene clusters in human, chimpanzee, and baboon.

We have previously identified a cluster of 16 genes that encode hair-specific proteins, called keratin-associated proteins (KAPs), located on human Chromosome (Chr) 21q22.3. Here, we have identified similar KAP gene clusters in two primates, chimpanzee and baboon. DNA sequence comparison revealed the common cluster structure consisting of 16 KAP genes for these three primates, but a significant difference was found in the baboon. Baboon possesses a new KAP gene not found in human and chimpanzee, whereas one KAP gene ( KRTAP18.12) that exists in human and chimpanzee was lost in baboon, making no change in the total number of KAP genes. Interestingly, the sequence for coding regions are highly variable among species owing to insertions and deletions, resulting in variation of gene size. On the contrary, the sequences for the 5' upstream region are highly conserved among species. These findings suggest that the ancestral KAP gene cluster was composed of 17 genes before the divergence of Old World monkeys (baboon) to the anthropoid (human and chimpanzee).

Amino Acid Sequence↗
PubMed2004

Pegylated recombinant human megakaryocyte growth and development factor suppresses the development of megakaryoblastic leukemia in mice.

We examined the effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on the development of L-8057, a murine megakaryoblastic leukemia that expresses the thrombopoietin receptor c-Mpl, in mice. PEG-rHuMGDF administration prolonged survival of L-8057 leukemic mice, in which L-8057 cell growth in the spleen was decreased. L-8057 cells harvested from PEG-rHuMGDF-treated leukemic mice had decreased ability to generate leukemic colonies in vitro as well as to induce leukemia in vivo. PEG-rHuMGDF administration also resulted in prolonged survival of mice transplanted with a c-Mpl-expressing erythroleukemia, but had no effect on survival of mice transplanted with a myeloblastic leukemia that does not possess c-Mpl. Thus, PEG-rHuMGDF suppresses the development of c-Mpl-expressing leukemia in vivo in mice.

Animals↗
PubMed2004

A cluster of 21 keratin-associated protein genes within introns of another gene on human chromosome 21q22.3.

Recently, we identified multiple unique sequences in the 21q22.3 region and predicted them to be a cluster of genes encoding hair-specific keratin-associated proteins (KAPs). Detailed computer-aided analysis of these clustered genes revealed that the cluster spans over 165 kb and consists of 21 KAP-related sequences including 16 putative genes and 5 pseudogenes. These were further divided into two subfamilies, KRTAP12 (KRTAP12.1-12.4 and KRTAP12.5P) and KRTAP18 (KRTAP18.1-18.12 and KRTAP18.13P-18.16P). All 16 putative genes possess several intragenic repeat sequences and apparently belong to the high-sulfur KAP gene family (16-30% cysteine content) known for nonhuman mammalian species. Transcripts were detected by RT-PCR analysis for all 16 putative KAP genes and their expression was restricted to hair root cells (radix pili cells) and not found in 28 other tissues, including skin. All 16 KAP genes produced unspliced transcripts, indicating their nature to be that of active intronless genes. Interestingly, all these KAP-related genes are located within introns of the recently identified gene TSPEAR (approved gene symbol C21orf29), 214 kb in size. Surprisingly, the transcriptional direction of 8 of the 16 active genes is the same as that of C21orf29/TSPEAR. This finding suggests a novel transcription mechanism in which C21orf29/TSPEAR gene transcription passes over the multiple transcriptional termination sites of the KAP genes.

Amino Acid Sequence↗
PubMed2002

The transmembrane serine protease (TMPRSS3) mutated in deafness DFNB8/10 activates the epithelial sodium channel (ENaC) in vitro.

TMPRSS3 encodes a transmembrane serine protease that contains both LDLRA and SRCR domains and is mutated in non-syndromic autosomal recessive deafness (DFNB8/10). To study its function, we cloned the mouse ortholog which maps to Mmu17, which is structurally similar to the human gene and encodes a polypeptide with 88% identity to the human protein. RT-PCR and RNA in situ hybridization on rat and mouse cochlea revealed that Tmprss3 is expressed in the spiral ganglion, the cells supporting the organ of Corti and the stria vascularis. RT-PCR on mouse tissues showed expression in the thymus, stomach, testis and E19 embryos. Transient expression of wild-type or tagged TMPRSS3 protein showed a primary localization in the endoplasmic reticulum. The epithelial amiloride-sensitive sodium channel (ENaC), which is expressed in many sodium-reabsorbing tissues including the inner ear and is regulated by membrane-bound channel activating serine proteases (CAPs), is a potential substrate of TMPRSS3. In the Xenopus oocyte expression system, proteolytic processing of TMPRSS3 was associated with increased ENaC mediated currents. In contrast, 6 TMPRSS3 mutants (D103G, R109W, C194F, W251C, P404L, C407R) causing deafness and a mutant in the catalytic triad of TMPRSS3 (S401A), failed to undergo proteolytic cleavage and activate ENaC. These data indicate that important signaling pathways in the inner ear are controlled by proteolytic cleavage and suggest: (i) the existence of an auto-catalytic processing by which TMPRSS3 would become active, and (ii) that ENaC could be a substrate of TMPRSS3 in the inner ear.

Animals↗
PubMed2002

Marked improvement of thrombocytopenia in a murine model of idiopathic thrombocytopenic purpura by pegylated recombinant human megakaryocyte growth and development factor.

OBJECTIVE: We examined the stimulatory effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet production in male (NZW x BXSB) F(l) (W/B F(1)) mice, a murine model of idiopathic thrombocytopenic purpura. MATERIALS AND METHODS: A cohort of 19- to 25-week-old, severely thrombocytopenic male W/B F(1) mice were given PEG-rHuMGDF at different dosing schedules. Before and at various times after therapy, platelet counts, reticulated platelets, platelet lifespan, and levels of platelet-associated immunoglobulin G were measured. Analysis of megakaryocytic cells was performed. RESULTS: Treatment of male W/B F(1) mice with PEG-rHuMGDF (30 microg/kg/day) three times per week for several weeks resulted in sustained thrombocytosis, accompanied by increased megakaryocytopoiesis in both the bone marrow and spleen. The degree of the platelet response to PEG-rHuMGDF varied between individual mice, likely reflecting the heterogeneity of the disease. Production of new platelets in response to PEG-rHuMGDF was manifested by an increase in reticulated platelets. Levels of platelet-associated immunoglobulin G decreased inversely during periods of thrombocytosis. PEG-rHuMGDF therapy also improved thrombocytopenia in male W/B F(1) mice refractory to splenectomy. Platelet lifespan was not affected by PEG-rHuMGDF. Male W/B F(1) mice treated with pegylated murine MGDF, a homologue of PEG-rHuMGDF, had persistent thrombocytosis for at least 7 months, suggesting that antiplatelet antibody production was not enhanced. CONCLUSIONS: PEG-rHuMGDF therapy potently stimulated platelet production, effectively ameliorating thrombocytopenia in a murine model of idiopathic thrombocytopenic purpura.

Animals↗