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Masuko Katoh

Publications and source records attributed to Masuko Katoh.

At least 37 records · Page 2Linked to original sources

Comparative genomics on Wnt7a orthologs.

WNT and Hedgehog signaling pathways network together during carcinogenesis and embryogenesis. WNT7A mRNA is expressed in human gastric and pancreatic cancer cells. WNT7A mRNA expression is relatively high in the temporal, occipital and parietal lobes, paracentral gyrus of the cerebral cortex, caudate nucleus, hippocampus, medulla oblongata and putamen within the adult human brain. Here, we identified and characterized the rat Wnt7a gene using bioinformatics. The rat Wnt7a gene, consisting of four exons, was located within the AC106100.7 genome sequence. Rat Wnt7a (349 aa) with 24 Cys residues and 3 Asn-linked glycosylation sites showed 99.7, 99.1 and 93.7% total-amino- acid identity with mouse Wnt7a, human WNT7A and chicken wnt7a, respectively. The N-terminal signal peptide was not identified within the Wnt7a orthologs. Exonic regions, except the 3'-UTR, were conserved between the rat Wnt7a and human WNT7A genes; however, the 5'-flanking region was significantly divergent between the rat Wnt7a and human WNT7A genes. Although the COMP1- and ELK1-binding sites within exon 1 were conserved among mammalian Wnt7a promoters, transcriptional regulation of the rodent Wnt7a orthologs was predicted to be distinct from that of human WNT7A based on the divergence within the 5'-flanking promoter region. Therefore, biological functions of rodent Wnt7a are not always consistent with those of human WNT7A due to promoter evolution. This is the first report on the rat Wnt7a gene and comparative genomics for Wnt7a orthologs.

Animals↗

Comparative genomics on Norrie disease gene.

DAND1 (NBL1), DAND2 (CKTSF1B1 or GREM1 or GREMLIN), DAND3 (CKTSF1B2 or GREM2 or PRDC), DAND4 (CER1), DAND5 (CKTSF1B3 or GREM3 or DANTE), MUC2, MUC5AC, MUC5B, MUC6, MUC19, WISP1, WISP2, WISP3, VWF, NOV and Norrie disease (NDP or NORRIN) genes encode proteins with cysteine knot domain. Cysteine-knot superfamily proteins regulate ligand-receptor interactions for a variety of signaling pathways implicated in embryogenesis, homeostasis, and carcinogenesis. Although Ndp is unrelated to Wnt family members, Ndp is claimed to function as a ligand for Fzd4. Here, we identified and characterized rat Ndp, cow Ndp, chicken ndp and zebrafish ndp genes by using bioinformatics. Rat Ndp gene, consisting of three exons, was located within AC105563.4 genome sequence. Cow Ndp and chicken ndp complete CDS were derived from CB467544.1 EST and BX932859.2 cDNA, respectively. Zebrafish ndp gene was located within BX572627.5 genome sequence. Rat Ndp (131 aa) was a secreted protein with C-terminal cysteine knot-like (CTCK) domain. Rat Ndp showed 100, 96.9, 95.4, 87.8 and 66.4 total-amino-acid identity with mouse Ndp, cow Ndp, human NDP, chicken ndp and zebrafish ndp, respectively. Exon-intron structure of mammalian Ndp orthologs was well conserved. FOXA2, CUTL1 (CCAAT displacement protein), LMO2, CEBPA (C/EBPalpha)-binding sites and triple POU2F1 (OCT1)-binding sites were conserved among promoters of mammalian Ndp orthologs.

Amino Acid Sequence↗

Comparative genomics on nemo-like kinase gene.

WNT signals are transduced to the planar cell polarity (PCP) pathway or the beta-catenin pathway. Drosophila Frizzled (Fz), Starry night (Stan), Van Gogh (Vang), Dishevelled (Dsh), Prickle (Pk), Diego (Dgo) and Nemo (Nmo) are implicated in the PCP signaling pathway. Choi and Benzer identified Drosophila Nmo in 1994, and Brott et al identified mouse Nemo-like kinase (Nlk) in 1998. Nlk positively regulates the PCP pathway, and negatively regulates the beta-catenin pathway. Here, we identified and characterized rat Nlk gene, Nlk2 gene and Nlkp pseudogene by using bioinformatics. Nlk gene, consisting of 11 exons, was mapped to rat chromosome 10q25. Rat Nlk gene encoded 515-aa Nlk protein with the serine/threonine kinase domain, poly(His) tracts and poly(Ala) tract, which showed 100, 99.8, 97.1 and 89.5% total-amino-acid identity with mouse Nlk, human NLK, Xenopus nlk and zebrafish nlk, respectively. Rat Nlk2 gene and Nlkp pseudogene were mapped to rat chromosome 13p13 and 2q44, respectively. Nlk2 gene and Nlkp pseudogene, consisting of a single exon, were not evolutionarily conserved. Nlk2 gene and Nlkp pseudogene were predicted as retrotransposed Nlk homologs within the rat genome. Nlk2 gene encoded a 480-aa Nlk2 protein with partial deletion within the kinase domain, which was predicted as the dominant negative Nlk homolog. This is the first report on the Nlk gene and retrotransposed Nlk homologs within the rat genome.

Amino Acid Sequence↗

Identification and characterization of rat Dact1 and Dact2 genes in silico.

DACT1 (DAPPER1), Frizzled receptors, MUSK receptor, VANGL1, VANGL2, PRICKLE1, PRICKLE2, DAAM1, Casein kinases, MARK3 (PAR1), PP2C, AXIN1, AXIN2, NKD1, NKD2, FRAT1, FRAT2 and CXXC4 are WNT signaling molecules associating with Dishevelled family proteins. Human DACT1 is the ortholog of Xenopus Dapper and Frodo, and human DACT2 (DAPPER2) is the paralog of human DACT1. Here, we identified and characterized rat Dact1 (Dapper1) and Dact2 (Dapper2) genes by using bioinformatics. Rat Dact1 gene, consisting of four exons, was located within AC136677.3 genome sequence. Rat Dact2 gene, consisting of four exons, was located within AC139434.3 genome sequence. Dact1 was mapped to rat chromosome 6q24, and Dact2 gene to rat chromosome 1q12. Rat Dact1 (778 aa) showed 93.7, 82.9, 60.3, 58.7 and 48.6% total-amino-acid identity with mouse Dact1, human DACT1, Xenopus Dapper, Xenopus Frodo and zebrafish dact1, respectively. Rat Dact2 (768 aa) showed 86.6, 59.6 and 38.3% total-amino-acid identity with mouse Dact2, human DACT2 and zebrafish dact2, respectively. Dact1 orthologs were more evolutionarily conserved than Dact2 orthologs. Seven DAPH domains (DAPH1-DAPH7), originally identified as the regions conserved between human DACT1 and DACT2, were conserved among mammalian Dact1 orthologs and Dact2 orthologs. DAPH2 domain, corresponding to the Leucine zipper motif, was located within the coiled-coil region. DAPH3 domain was the Serine rich region. DAPH7 domain was the C-terminal PDZ binding region. This is the first report on the rat Dact1 and Dact2 genes.

Adaptor Proteins, Signal Transducing↗

Comparative genomics on Fzd7 orthologs.

WNT signaling pathway networks with Hedgehog and Notch signaling pathways during carcinogenesis and embryogenesis. FZD7 is up-regulated in gastric cancer, esophageal cancer, and hepatocellular carcinoma (HCC). Here we identified and characterized rat Fzd7 gene by using bioinformatics. Rat Fzd7 gene was identified within AC136379.2 genome sequence. The 5'-flanking region and exonic region were well conserved among mammalian Fzd7 orthologs. Nucleotide position 153000-152216 of AC136379.2 genome sequence was identified as the evolutionarily conserved promoter region of rat Fzd7 gene, and nucleotide position 2273-3046 of AC069148.6 genome sequence as the evolutionarily conserved promoter region of human FZD7 gene. Match program revealed that PAX4-binding site was conserved among rat Fzd7, mouse Fzd7 and human FZD7 promoters. Rat Fzd7 (572 aa) was a seven-transmembrane-type Wnt receptor, which showed 99.3, 96.9, 87.4, 85.5, 79.5 and 79.0% total-amino-acid identity with mouse Fzd7, human FZD7, chicken fzd7, Xenopus fzd7, zebrafish fzd7a and fzd7b, respectively. Frizzled (Fz) domain within the N-terminal extracellular region, Leucine zipper motif around the fifth transmembrane (TM5) region, Dishevelled (Dvl)- and Magi3-binding motifs within the C-terminal cytoplasmic region were conserved among vertebrate Fzd7 orthologs. Leucine zipper motif around the TM5 region of Fzd7 orthologs was disrupted in FzE3 aberrant cDNA due to multiple cloning artifacts or sequencing errors. These facts indicate that experimental data obtained by using FzE3 cDNA do not always reflect the functions of Fzd7 orthologs.

Amino Acid Motifs↗

Comparative genomics on mammalian Fgf3-Fgf4 locus.

The CCND1-ORAOV1-FGF19-FGF4-FGF3-TMEM16A-FADD-PPFIA1-CTTN (EMS1) locus at human chromosome 11q13.3 is amplified in head and neck tumors, esophageal cancer, Kaposi's sarcoma, bladder tumors, breast cancer, and liver cancer. Fgf4 mRNA is expressed in embryonic stem (ES) cells depending on Sox2 and Pou5f1 (Oct3/Oct4) transcription factors, and in myotomes and limb bud AER depending on MyoD (or Myf5) and GATA transcription factors. Here, rat Fgf3 and Fgf4 complete coding sequences were determined by using bioinformatics. Multiple errors, including one-base insertion and 22-base deletion, were identified within the coding region of rat Fgf4 RefSeq (NM_053809.1 or AB079673.1). Rat Fgf3 and Fgf4 genes, consisting of three exons, were clustered in tail-to-head manner with an interval of about 16 kb. CUTL1 (CCAAT-displacement protein, CDP) and NKX2-5 binding sites and TATA box within 5'-flanking promoter region were conserved among human, rat and mouse Fgf3 orthologs. MYOD and MYOG (Myogenin) binding sites and TATA box within 5'-flanking promoter region as well as GATA, MYOD, SOX2 and POU5F1 binding sites within exon 3 were conserved among mammalian Fgf4 orthologs. Human FGF3 and FGF4 genes were clustered in tail-to-head manner with an interval of about 35 kb. Major repetitive sequence (FGF34Rep1) and minor repetitive sequence (FGF34Rep2) were identified within human FGF3-FGF4 gene cluster. FGF34Rep1 were clustered within the FGF3-FGF4 locus as well as around the IL28RA locus (1p36.11) and the NFAM1 locus (22q13.2). FGF34Rep2 was characterized by the CCA(T/C) repeats. This is the first report on comparative genomics analyses on the Fgf3-Fgf4 locus within human, rat and mouse genomes.

Amino Acid Sequence↗

Comparative genomics on FGF20 orthologs.

We cloned and characterized human FGF20 in August, 2000. Ohmachi et al claimed the same gene as a novel FGF family member in October, 2000, and Jeffers et al in April, 2001. FGF20 is up-regulated in colorectal cancer due to the activation of WNT/beta-catenin pathway. FGF20 is applicable as the mucosal protective agent for inflammatory bowel disease and chemotherapy/radiation-induced oral mucositis, and also as the inducer of dopaminergic neurons for Parkinson's disease. FGF20 is a target of pharmacogenomics in the field of oncology and regenerative medicine. Here, comparative genomics analyses on FGF20 orthologs were performed. Zebrafish fgf20 gene, consisting of three exons, was located within BX323810.8 genome sequence. Zebrafish fgf20 (208 aa) showed 76.9%, 76.4%, 76.0% and 75.5% total-amino-acid identity with human FGF20, Xenopus fgf20, rat Fgf20 and mouse Fgf20, respectively. Fgf20 orthologs were well conserved among vertebrates. Human FGF20 gene was linked to EFHA2 gene in head-to-head manner with an interval of about 25 kb. FGF20-EFHA2 locus at human chromosome 8p22 and FGF9-EFHA1 locus at human chromosome 13q12.11 were paralogous regions (paralogons) within the human genome. The 5'-flanking promoter region, exonic regions except 3'-UTR, and middle regions within intron 1 were conserved between human FGF20 and mouse Fgf20 genes. Double TCF/LEF binding sites, double EVI1-binding sites, TGIF, PAX4, E47 and AREB6-binding sites were conserved between human FGF20 promoter and mouse Fgf20 promoter.

Amino Acid Sequence↗

Comparative genomics on FGF8, FGF17, and FGF18 orthologs.

FGF and WNT signaling pathways network together during embryogenesis and carcinogenesis. Among 22 FGF family members within human and rodents genomes, FGF20 orthologs are evolutionarily conserved targets of the WNT/beta-catenin signaling pathway. FGF8, FGF17, and FGF18 constitute one of FGF subfamilies. Here, comparative proteomics and comparative genomics analyses on FGF8, FGF17, and FGF18 orthologs were performed. Rat Fgf8 and Fgf17 genes, consisting of five exons, were located within AC096326.7 and AC097410.12 genome sequences, respectively. FGF8, FGF17, and FGF18 orthologs were FGF family members with the N-terminal signal peptide. Human FGF8 isoform F showed 90.6% total-amino-acid identity with rat Fgf8 (268 aa). Human FGF17 showed 98.6% total-amino-acid identity with rat Fgf17 (216 aa). Human FGF18 also showed 98.6 total-amino-acid identity with rat Fgf18. FBXW1 (betaTRCP1 or BTRC1)-FGF8-NPM3 locus at human chromosome 10q24.32, FBXW11 (betaTRCP2 or BTRC2)-FGF18-NPM1 locus at human chromosome 5q35.1, and FGF17-NPM2 locus at human chromosome 8p21.3 were paralogous regions within the human genome. FGF8 mRNA was expressed in DMSO-treated embryonic stem (ES) cells. FGF17 mRNA was expressed in ES cells differentiated to an early endodermal phenotype. FGF18 mRNA was expressed in fetal lung, fetal heart, lung carcinoid, colorectal cancer, and ovarian cancer. FGF18 promoter with double TCF/LEF binding sites rather than FGF8 promoter and FGF17 promoter was more conserved between human and rodents. These facts indicate that FGF18 orthologs were evolutionarily conserved targets of the WNT/beta-catenin signaling pathway.

Amino Acid Sequence↗

Comparative genomics on SFRP2 orthologs.

SFRP1, SFRP2, SFRP3, SFRP4, SFRP5, DKK1, DKK2, DKK3, DKK4, and WIF1 are soluble modulators of WNT signaling. SFRP2 gene at human chromosome 4q31.3 is claimed as a tumor suppressor gene inactivated by the epigenetic CpG hypermethylation in colorectal cancer. SFRP2 methylation is a sensitive single DNA-based marker for the fecal screening of colorectal cancer. On the other hand, SFRP2 is claimed to induce cellular resistance to apoptosis in mammary tumors. Here, we identified and characterized the rat Sfrp2 gene by using bioinformatics. Rat Sfrp2 gene, consisting of three exons, was located within AC129161.3 genome sequence. Rat Sfrp2 gene was found to encode a 295-aa Sfrp2 protein, consisting of signal peptide, Frizzled domain with ten conserved Cys residues, and Netrin (NTR) domain with six conserved Cys residues. Rat Sfrp2 showed 98.6% and 97.6% total-amino-acid identity with mouse Sfrp2 and human SFRP2, respectively. Phylogenetic analyses revealed that Sfrp2 orthologs were more related to Sfrp1 and Sfrp5 orthologs than to Sfrp3 and Sfrp4 orthologs. Human SFRP2 promoter (nucleotide position 71417-71152 of AC020703.7 genome sequence) and rat Sfrp2 promoter (nucleotide position 184090-184357 of AC129161.3 genome sequence) showed 88.7% total nucleotide identity. GC content of human SFRP2 promoter was 63.9%. Binding site for POU domain transcription factors (POU2F1, POU2F2, etc.) was conserved between human SFRP2 promoter and rat Sfrp2 promoter. SFRP2 mRNA was expressed in embryonic stem (ES) cells, diffuse type gastric cancer with signet ring cell features, pancreatic cancer, colorectal cancer, retinoblastoma, and insulinoma. This is the first report on comparative integromics analyses on SFRP2 orthologs.

Amino Acid Sequence↗

Comparative genomics on SNAI1, SNAI2, and SNAI3 orthologs.

SNAI1, SNAI2, and SNAI3 genes, encoding transcriptional repressors implicated in epithelial mesenchymal transition (EMT), are human homologs of Drosophila snail (sna) and slug genes. SNAI1 represses transcription of CDH1 (E-cadherin) gene. SNAI2 induces the first phase of EMT, including desmosome dissociation, cell spreading, and initiation of cell separation. Because SNAI family proteins are implicated in EMT during embryogenesis and carcinogenesis, SNAI family genes are potent targets of pharmacogenomics. Here, comparative genomics analyses and comparative proteomics analyses on SNAI family orthologs were performed. Rat Snai3 gene, consisting of three exons, was identified within rat genome sequence AC111791.4. Zebrafish snai1a (NM_131066.1) was identified as SNAI1 ortholog. Chicken ChEST362l17 (CR407272.1), Xenopus slug (AF368041.1), and zebrafish zgc92564 (NM_001008581.1) were identified as SNAI2 orthologs. Chicken snail (NM_ 205142.1), Xenopus snail (BC056857.1), and zebrafish snai1b (NM_130989.1) were identified as SNAI3 orthologs. SNAI1 orthologs consisted of SNAG domain and four zinc finger (ZNF) domains, while SNAI2 and SNAI3 orthologs consisted of SNAG domain and five ZNF domains. Based on the integromics analyses, SNAI2 orthologs were found to be more conserved than SNAI1 and SNAI3 orthologs. SNAI1 mRNA was expressed in placenta, neuroblastoma, and diffuse type gastric cancer. SNAI2 mRNA was expressed in placenta, melanocyte, embryonic stem (ES) cells, leiomyosarcoma, neuroblastoma, and glioblastoma. SNAI3 mRNA was expressed in B cells. Expression of SNAI3 mRNA was repressed due to the existence of anti-sense single-exon transcript. SNAI1, functioning as E-cadherin repressor, is implicated in the malignant infiltrating phenotype of diffuse type gastric cancer through the induction of EMT or fibroblastoid transformation.

Amino Acid Sequence↗

Pharmacogenomics on gastric cancer.

Gastric cancer is one of most common malignancies in the world. 5-fluoroyracil, CPT-11, TS-1, Paclitaxel and Docetaxel are used as chemotherapeutic agents for advanced gastric cancer, although endoscopic mucosal resection and surgical gastrectomy are potentially curative treatments. Most important problems associated chemotherapeutic agents are side effects and drug resistances. TSG101, implicated in membrane trafficking and transcriptional regulation, is upregulated in gastric cancer with multidrug resistant phenotype. Shen et al reported that transient transfection of TSG101 siRNA reduced the expression level of TSG101 protein as well as resistance to vincristine and adriamycin in gastric cancer cells. Bioinformatics, microarray analyses, SNP typing, and high-throughput functional analyses are applied for pharmacogenomics in the post-genome era. Therapeutics based on the genotyping of each patient is the future goal of personalized medicine (or tailor-made medicine) for gastric cancer.

Antineoplastic Agents↗

Identification and characterization of human FNBP1L gene in silico.

FNBP1/FBP17/Rapostlin and TRIP10/CIP4 are structurally related microtubule-binding proteins involved in the regulation of cell shape, polarity, motility, and signal transduction. Here, we identified and characterized the FNBP1-like (FNBP1L) gene by using bioinformatics. Human FLJ20275 (NM_017737.1) and mouse 2610318I01Rik (NM_153118.1) were 5'-truncated partial cDNAs derived from human FNBP1L gene and mouse Fnbp1l gene, respectively. Exons 1-7 of FNBP1L gene were located within human genome sequence AL512651.13, and exons 7-15 within AL109613.11. Complete coding sequence of FNBP1L was determined in silico by assembling nucleotide sequences of FNBP1L exons. FNBP1L (547 aa) showed 59.4 and 55.4% total-amino-acid identity with FNBP1 and TRIP10, respectively. FNBP1L, FNBP1 and TRIP10 shared the common domain structure, consisting of FCH, FBH, HR1 and SH3 domains. FCH domain of FNBP1 family proteins is the microtubule-binding domain. HR1 (also known as antiparallel coiled-coil finger) is the binding domain for Rho family proteins, such as ARHN/RhoN and CDC42. SH3 domain of FNBP1 family proteins interacts with proline-rich region of Formin and WASP family proteins. FNBP1L gene was linked to SH2D3B/BCAR3 gene in tail-to-tail manner with an interval less than 8 kb within the human genome. FNBP1L-SH2D3B locus at human chromosome 1p22.1 was paralogous to GPR108-TRIP10-SH2D3A locus at 19p13.3 and GPR107-FNBP1-SH2D3C locus at 9q34.11-q34.13. This is the first report on comprehensive characterization of FNBP1L, which is predicted to function as a scaffold protein for microtubule, Rho family proteins, Formin-homology proteins and WAPS family proteins.

Amino Acid Sequence↗

Identification and characterization of human MPP7 gene and mouse Mpp7 gene in silico.

Drosophila Crumbs (Crb), Stardust (Sdt), Discs large (Dlg), Scribble (Scrib) and Lethal giant larvae (Lgl) are involved in the establishment and the maintenance of apicobasal polarity in epithelial tissues. Because epithelial polarity is disrupted in tumors, human homologs of Drosophila crb, sdt, dlg, scrib, and lgl are potential cancer-associated genes. MPP1/EMP55, MPP2, MPP3, MPP4, MPP5/PALS1 and MPP6/PALS2 genes are human homologs of Drosoplila sdt. Here, we identified and characterized a novel member of MPP gene family, MPP7, by using bioinformatics. Uncharacterized FLJ32798 cDNAs (BC038105 and AK057360) were derived from human MPP7 gene. BC038105 was a representative MPP7 cDNA, while AK057360 was an aberrant MPP7 cDNA with a frame shift. Human MPP7 mRNA was expressed in placenta, brain, testis as well as in uterus tumor, bladder tumor, and lymphoma. Microsatellite marker D10S588, linked to IDDM and hereditary thrombocytopenia, was located within the MPP7 gene at human chromosome 10p12.1. Nucleotide sequence of mouse Mpp7 cDNA was determined in silico by assembling 3'-truncated cDNA AK078849, genome clone RP24-255J24, and EST AV260217. Human MPP7 showed 92.9% total-amino-acid identity with mouse Mpp7, and 75.7% total-amino-acid identity with zebrafish humpback. MPP7 orthologs were MAGUK proteins with two L27 domains, PDZ domain, SH3 domain, and GuKc domain. MPP7 was most related to MPP3 among MPP family members, functioning as adopter molecules assembling Crb homologs (CRB1, CRB3), Dlt homologs (INADL/PATJ, MPDZ/MUPP1), and Lin-7 homologs (LIN7A, LIN7B, LIN7C). This is the first report on identification and characterization of human MPP7 and mouse Mpp7 genes.

Amino Acid Sequence↗

Identification and characterization of human LLGL4 gene and mouse Llgl4 gene in silico.

Drosophila Discs large (Dlg), Scribble (Scrib) and Lethal giant larvae (Lgl) act in concert as regulators of epithelial polarity, and human homologs of Drosophila dlg, scrib, and lgl are cancer-associated genes. LLGL1, LLGL2, and LLGL3/STXBP5 genes, encoding LGL1, LGL2, and LGL3/Tomosyn, respectively, are human homologs of Drosophila lgl gene. Here, we identified and characterized LLGL4 (also known as STXBP5L) gene encoding LGL4 protein, by using bioinformatics. Uncharacterized human KIAA1006 cDNA (AB023223) was derived from human LLGL4 gene. LLGL4 mRNA was expressed in kidney, brain hippocampus, and also in lung carcinoid, and germ cell tumors. LLGL4 gene, consisting of 28 exons, was mapped to human chromosome 3q13.33. Mouse A830015P08Rik cDNA (NM_172440.1) was a 3'-truncated partial Llgl4 cDNA. Nucleotide sequence of full-length mouse Llgl4 cDNA was determined in silico by assembling A830015P08Rik cDNA, BU609516 EST and last two exons of Llgl4 gene within mouse genome clone RP24-174G4 (AC118742.3). Human LGL4 showed 95.8% total-amino-acid identity with mouse Lgl4, and 68.4% total-amino-acid identity with human LGL3. LGLH1 domain (codon 1-11 of LGL4), LGLH2 domain (codon 52-98) and LGLH3 domain (codon 994-1054) were identified as novel conserved regions among LGL family members. LGL1 and LGL2 consist of LGLH1, LGLH2, LGLH3 domains and five WD40 repeats, while LGL3 and LGL4 consist of LGLH1, LGLH2, LGLH3 domains, five WD40 repeats and the C-terminal Syntaxin-binding SNARE domain. This is the first report on identification and characterization of human LLGL4 and mouse Llgl4 genes.

Adaptor Proteins, Vesicular Transport↗

Identification and characterization of Crumbs homolog 2 gene at human chromosome 9q33.3.

Drosophila Crumbs (Crb)--Stardust (Sdt)--Discs lost (Dlt) complex plays a pivotal role in the establishment and the maintenance of epithelial polarity. CRB1 and CRB3 are human homologs of Drosophila Crb, MPP1-MPP7 are human homologs of Drosophila Sdt, INADL/PATJ and MPDZ/MUPP1 are human homologs of Drosophila Dlt. Here, we identified and characterized a novel Crumbs family gene, Crumbs homolog 2 (CRB2), by using bioinformatics. CRB2 isoform 1 was assembled by adding nucleotide position 1-3353 of FLJ16786 cDNA (AK123000) to the 5'-end of 5'-truncated FLJ38464 cDNA (NM_173689.1), while that of CRB2 isoform 2 was derived from FLJ16786 cDNA. CRB2 isoform 1, consisting of exon 1-13, encoded a 1285-aa transmembrane protein. CRB2 isoform 2, consisting of exon 1-10 and intron 10, encoded a 1176-aa secreted protein. CRB2 gene was found to encode transmembrane protein as well as secreted protein due to alternative splicing. CRB2 isoform 1, showing 24.4% total amino-acid identity with CRB1, was type I transmembrane protein with 14 extracellular EGF-like domains, 3 extracellular Laminin G-like domains and the Crb cytoplasmic tail (CCT) domain. CCT domain, functioning as the binding site for PDZ domain of Sdt homologs, was conserved among human CRB1, CRB2, CRB3, mouse Crb1, Crb3, Drosophila Crb, and C. elegans crb. Comparative genomics revealed that CRB2-KIAA1608-LHX2-NEK6 locus at human chromosome 9q33.3 and CRB1-MGC27044-LHX9-NEK7 locus at human chromosome 1q31.3 were paralogous regions within the human genome. This is the first report on identification and characterization of the CRB2 gene.

Alternative Splicing↗

Identification and characterization of human DIAPH3 gene in silico.

Formin homology proteins with FH1 and FH2 domains are signaling effectors for assembly and polarization of actin filaments. FH1 is the binding domain for Profilin, SRC, EMS1/Cortactin, FNBP1, FNBP2, FNBP3, FNBP4 and WBP4/Fbp21, while FH2 is the actin-filament modification domain. Here, we identified and characterized a novel member of Formin-homology gene family, Diaphanous homology 3 (DIAPH3), by using bioinformatics. DIAPH3 isoform 1, corresponding to 3'-truncated FLJ34705 cDNA and 5'-divergent IMAGE5265490 cDNA, encodes full-length DIAPH3 protein (1112 aa), while DIAPH3 isoform 2, identical to NM_030932.2 cDNA, encodes N-terminally truncated DIAPH3 protein (849 aa). DIAPH3 isoform 1, consisting of exons 1-27, was expressed in lymph node, erythroid progenitor cells as well as in pancreatic cancer. DIAPH3 isoform 2, consisting of exons 1b and 8-27, was expressed in testis. DIAPH3 gene at human chromosome 13q21.2 was found to encode two isoforms due to alternative splicing of the alternative promoter type. Full-length human DIAPH3 protein, consisting of FDD, FH1 and FH2 domains, showed 51.3% total-amino-acid identity with DIAPH1, and 57.3% total-amino-acid identity with DIAPH2. FMNL1/FMNL, FMNL2/FHOD2, FMNL3/WBP3, DAAM1, DAAM2, DIAPH1, DIAPH2 and DIAPH3 were classified as the FDD-type Formin homology proteins, while GRID2IP/Delphilin, FHOD1, Fmn1 and Fmn2 were classified as the non-FDD-type Formin homology proteins. This is the first report on identification and characterization of human DIAPH3 gene.

Adaptor Proteins, Signal Transducing↗

Evolutionary recombination hotspot around GSDML-GSDM locus is closely linked to the oncogenomic recombination hotspot around the PPP1R1B-ERBB2-GRB7 amplicon.

PPP1R1B-STARD3-TCAP-PNMT-PERLD1-ERBB2-MGC14832-GRB7 locus at human chromosome 17q12 is frequently amplified in human gastric cancer and breast cancer. Here, we compared human GSDML-GSDM locus with rodent genomes by using bioinformatics. Rodent ortholog of human GSDML was not identified. Rat Gsdm gene was identified within rat genome clone CH230-28N16 (AC119462.4), and was mapped to rat chromosome 10q31. Rat Gsdm gene, consisting of 12 exons, encoded a 446-amino-acid protein, which showed 86.3% and 32.3% total-amino-acid identities with human GSDM and GSDML, respectively. Mouse Gsdm-like 1 (Gsdml1) and Gsdml2 genes were identified within mouse genome clone RP23-438D7 (AL591125.20). Gsdml1 and Gsdml2 genes were found to encode 456- and 443-amino-acid proteins, respectively. Mouse 2200001G21Rik cDNA (AK008613.1) was a partial cDNA derived from mouse Gsdml2 gene. Mouse Gsdml1 and Gsdml2 were also more homologous to human GSDM than to human GSDML. Mouse Gsdml1, Gsdml2 and Gsdm genes, existing in the tandem homologous gene cluster, was mapped to mouse chromosome 11D. Mouse Gsdml1-Gsdml2-Gsdm gene cluster was predicted to be generated due to triplication of mouse Gsdm gene, while GSDML gene was predicted to be generated due to duplication of GSDM gene. Evolutionary recombination hotspot around the GSDML-GSDM locus was closely linked to the oncogenomic recombination hotspot around the PPP1R1B-ERBB2-GRB7 amplicon. The evolutionary recombination hotspot and oncogenomic recombination hotspot might be clustered around the fragile sites within the human genome.

Amino Acid Sequence↗