Identification and characterization of human ZPBP-like gene in silico

PP1R1B-ERBB2-GRB7 locus on human chromo-some 17q12 is frequently amplified in gastric and breast cancer. Because recombination hot spot or fragile site is located around the terminus of amplified region (amplicon), we searched for a novel gene closely linked to the teromeric end of the ERBB2 amplicon. Here, we identified and characterized the ZPBP-like (ZPBPL) gene by using bioinformatics. ZPBPL gene, corresponding to BC043152 cDNA, was found to consist of seven exons. ZPBPL (316 aa) and ZPBP (351 aa) proteins, showing 34.8% total amino-acid identity, shared the zona pellucida binding protein homologous (ZPBH) domain with conserved 15 cysteine residues. ZPBPL was a secreted-type glycoprotein with the ZPBH domain, while ZPBP was a type 2 transmembrane protein with the extracellular ZPBH domain. ZPBPL mRNA was co-expressed with ZPBP mRNA in testis, germ cell tumor, and brain medulla. ZPBPL might be implicated in the gamete interaction during fertilization just like ZPBP. The MGC9753-ERBB2-MGC14832-GRB7-ZNFN1A3-ZPBPL-PRO2521-ORMDL3-GSDM locus on human chromosome 17q12-q21 and the ZPBP-ZNFN1A1-FIGNL1-DDC-GRB10-COBL-SEC61G-EGFR-LANCL2 locus on human chromosome 7p12-p11 were next compared. Comparative genomics revealed that ZPBPL-ZNFN1A3-GRB7-ERBB2 and ZPBP-ZNFN1A1-GRB10-EGFR loci were paralogous regions within the human genome. This is the first report on identification and characterization of the ZPBPL gene.     

Identification and characterization of LASP2 gene in silico

LASP1 (also known as MLN50) gene, located centromeric to the PPP1R1B-ERBB2-GRB7 locus on human chromosome 17q12, is amplified and over-expressed in breast cancer. Here, we identified and characterized a novel LASP1-related gene, LASP2, by using bioinformatics. Nucleotide sequence of human LASP2 cDNA was determined in silico by assembling EST BF699808 and 5'-truncated FLJ39221 cDNA. Nucleotide sequence of mouse Lasp2 cDNA was derived from 1200007O21Rik cDNA. Human LASP2 (270 aa) showed 97.4% and 63.7% total-amino-acid identity with mouse Lasp2 and human LASP1, respectively. LASP2 and LASP1 were the LASP family proteins consisting of LIM domain, Nebulin repeat, and SH3 domain. LASP2 and NEBL mRNAs were transcribed from the LASP2/NEBL gene on human chromosome 10p12 due to alternative splicing. LASP2 mRNA consists of exons 1a-4a, 24, 27, and 28 of the LASP2/NEBL gene, while NEBL mRNA consists of exons 1-28. Exon 1a-4a of the LASP2/NEBL gene were more homologous to exon 1-4 of the LASP1 gene on human chromosome 17q12, while exon 1-28 of the LASP2/NEBL gene were more homologous to exons of NEB gene on human chromosome 2q23. Some part of the LASP2/ NEBL-TEM7L-ARL8-CACNB2 locus on 10p12 was paralogous to the LASP1-TEM7-CACNB1 locus on 17q12, while the other part of the LASP2/NEBL-TEM7L-ARL8-CACNB2 locus was paralogous to the NEB-ARL5-CACNB4 locus on 2q23. These facts indicate that the LASP2/NEBL-TEM7L-ARL8-CACNB2 is a chimeric locus, which might be generated through the homologous recombination between the ancestral lasp2-tem7l-cacnb2 locus and the ancestral nebl-arl8 locus. Therefore, gene fusion during evolution is one of the mechanisms to generate alternative splicing.     

Identification and characterization of human Inscuteable gene in silico

Neuroblast undergoes asymmetrical cell division to produce the neuroblast itself and ganglion mother cell along the apical-basal axis. Inscuteable (Insc) and Partner of Inscuteable (Pins) are translocated to the apical cell cortex during asymmetrical cell division of Drosophila neuroblast. Insc is implicated in the apical-basal orientation of mitotic spindle and the basal localization of Prospero (Pros) and Numb. Here, we identified and characterized human Inscuteable (INSC) gene using bioinformatics. Human INSC gene, consisting of at least 13 exons, was located within human genome draft sequence AC090744.5 (around nucleotide position 150581-16936 in reverse orientation). Human INSC gene, closely linked to CALCB gene with an interval of about 30 kb, was assigned to human chromosome 11p15.2-p15.1. Amino-acid sequence of human INSC polypeptide (579 aa) was determined based on exon sequences of human INSC gene. C. elegans hypothetical protein F43E2.3 (NP_495539), homologous to human INSC, was designated C. elegans Insc. Central INSC homologous (ISH) domain and C-terminal PDZ-binding motif were evolutionary conserved among INSC proteins. The former part of ISH domain is implicated in Pros localization, while function of the latter part of ISH domain and C-terminal PDZ-binding motif remain to be elucidated. Human INSC mRNA was expressed in eye, kidney, fetal cochlea, parathyroid tumor, chondrosarcoma, epidermoid carcinoma, and skin tumor. Because LGN/Pins, PARD3/Par-3Bazooka, PARD6A/Par-6 and PRKCZ/aPKC genes implicated in asymmetrical cell division are evolutionarily and functionally conserved, human INSC protein might be implicated in asymmetrical cell division of human neural stem cells and other stem cells.     

Identification and characterization of ARHGAP27 gene in silico

ARHGAP1, ARHGAP2, ARHGAP3, ARHGAP4, ARHGAP5, ARHGAP6, ARHGAP7 (DLC1), ARHGAP8, ARHGAP9, ARHGAP10, ARHGAP12, ARHGAP13 (SRGAP1), ARHGAP14 (SRGAP2), ARHGAP15, ARHGAP17 (RICH1), ARHGAP18, ARHGAP19, ARHGAP20, ARHGAP21, ARHGAP22, ARHGAP23, ARHGAP24, ARHGAP25, ARHGAP26, STARD13 (DLC2), HA-1, GMIP, PARG1, RACGAP1, PIK3R1, PIK3R2, and FNBP2 genes encode Rho/Rac/Cdc42-like GTPase activating (RhoGAP) proteins. Here, we characterized human ARHGAP27 gene by using bioinformatics. Complete coding sequence of ARHGAP27 isoform 1, encoding a full-length 889-aa protein, was determined by assembling exon 1 (nucleotide position 143440-144096 of AC091132.16) and most part of FLJ43547 cDNA (nucleotide position 69-3628 of AK125535.1). Complete coding sequence of ARHGAP27 isoform 2, encoding an N-terminally truncated 548-aa protein, was derived from FLJ43547 cDNA. ARHGAP27 isoform 1 consists of exons 1-17, while ARHGAP27 isoform 2 consists of exons 1B, and 2-17. ARHGAP27 gene encoded two isoforms due to alternative splicing of alternative promoter type. ARHGAP27 mRNA was expressed in germinal center B cell, spleen, chronic lymphocytic leukemia, pancreatic cancer, and lung cancer. LOC303583 (NM_ 198759.1) was the representative rat Arhgap27 cDNA. Human ARHGAP27 showed 84.3% total-amino-acid identity with rat Arhgap27, and 39.0% total-amino-acid identity with human ARHGAP12. ARHGAP27 and ARHGAP12 shared the common-domain structure, consisting of SH3, WW, PH, and RhoGAP domains. ARHGAP27 gene was located at human chromosome 17q21, while ARHGAP12 gene was located at human chromosome 10p11. ARHGAP family genes are cancer-associated genes, because their genetic alterations lead to carcinogenesis through the dysregulation of Rho/Rac/ Cdc42-like GTPases. This is the first report on identification and characterization of the ARHGAP27 gene.     

Identification and characterization of mouse Ppfia1 gene in silico

Array CGH combined with mRNA microarray analyses was successfully applied for genome-wide screening of proto-oncogenes and tumor suppressor genes in 2002. The CCND1-ORAOV1-FGF19-FGF4-FGF3-FLJ10261-FADD-PPFIA1-EMS1 locus on human chromosome 11q13 is one of the most frequently amplified regions within the human genome. Here, we identified and characterized mouse Ppfia1 gene by using bioinformatics. Nucleotide sequence of mouse Ppfia1 cDNA was determined in silico by assembling nucleotide sequences of ESTs BY727670, CA327608, BU708520, BQ886535, and a 5'-truncated partial cDNA BC038349. Mouse Ppfia1 gene, consisting of 28 exons, was located between Fadd and Ems1 (also known as Cttn) genes on mouse chromosome 7. Mouse Ppfia1 (1201 aa) and human PPFIA1 (1202 aa), showing 95.8% total-amino-acid identity, were found to consist of MAH (myosin heavy chain tail and ATPase homologous) domain and three SAM (sterile alpha motif) domains. MAH domain is implicated in the homo- or hetero-oligomer formation through the coiled-coil interaction, while SAM domain is implicated in the interaction with other proteins. Mouse Ccnd1-Ems1 locus and human CCND1-EMS1 locus were evolutionarily conserved in the order and the orientation of genes therein. Nucleotide and amino-acid substitution rates of Ccnd1, Ppfia1 and Ems1 genes located near both ends of the Ccnd1-Ems1 locus were relatively lower than those in the middle part of the locus. This is the first report on mouse Ppfia1 gene as well as comprehensive comparison of CCND1-EMS1 locus within the human and mouse genomes.     

Identification and characterization of human FHOD3 gene in silico

Formin homology proteins are actin regulators with scaffold function, which are implicated in organogenesis, normal tissue homeostasis, and cancer-cell invasion. FHOD1/FHOS, GRID2IP, Fmn1 and Fmn2 are non-FDD-type Formin homology proteins, while FMNL1, FMNL2/FHOD2, FMNL3, DAAM1, DAAM2, DIAPH1, DIAPH2 and DIAPH3 are FDD-type Formin homology proteins. Here, we identified and characterized FHOD3 (also known as FHOS2), a novel gene homologous to FHOD1, by using bioinformatics. Because FLJ46173, FLJ22297, KIAA1695 and FLJ34580 were partial FHOD3 cDNAs, complete coding sequence of FHOD3 cDNA was determined by assembling nucleotide sequences of FLJ46173 and FLJ22297. FHOD3 gene at human chromosome 18q12.2 was found consisting of at least 25 exons. Exon 11 of FHOD3 gene was spliced out in KIAA1695 cDNA and BF116064 EST, while exon 13 of FHOD3 gene was spliced out in FLJ46173 cDNA. FHOD3 gene encodes at least three isoforms due to alternative splicing of the exon skipping type. FHOD3 and FHOD1 showed 52.1% total-amino-acid identity. Drosophila CG32030 showed 43.9% total-amino-acid identity with human FHOD3, and 39.1% total-amino-acid identity with human FHOD1. FHDHN domain (codon 1-327 of FHOD3) and FHDHC domain (codon 1377-1421 of FHOD3) were identified as the N-terminal conserved region and the juxta C-terminal conserved region, respectively. Human FHOD3, FHOD1 and Drosophila CG32030 were found to share the conserved domain structure consisting of FHDHN, FH1, FH2, and FHDHC domains. This is the first report on the FHOD3 gene as well as on the novel FHDHN and FHDHC domains.     

Identification and characterization of human PPFIA4 gene in silico

Human PPFIA1 (also known as LIP.1 or Liprin alpha1) gene, located within CCND1-FGF4-EMS1 amplicon at human chromosome 11q13.3, encodes KIF1A-binding protein, which is implicated in trafficking of LAR subfamily PTPases and AMPA-type glutamate receptors. Human PPFIA4 (AF034801) and rat Ppfia4 (AY057064) are 5'-truncated partial cDNAs, and the complete coding sequence of PPFIA4 ortholog of any species remained to be identified. Here, we determined the complete coding sequence of human PPFIA4 gene by using bioinformatics. Exons 1-12 of PPFIA4 gene were located within human genome sequence AC096632.3, while exons 11-29 within AL451082.6. PPFIA4-MYOG locus (human chromosome 1q32.1) was paralogous to PPFIA2-LIN7A-MYF5-MYF6 locus (12q21.31), which was also paralogous to PPFIA3-LIN7B locus (19q13.41). PPFIA4 (1186 aa) showed 70.9%, 67.1%, and 61.8% total-amino-acid identity with PPFIA2, PPFIA1, and PPFIA3, respectively. PPFIA family members consist of PFIH1, PFIH2, PFIH3, PFIH4 domains and three SAM (Sterile alpha motif) domains. C-terminal binding domain for GRIP proteins (VRTYSC motif) was present in PPFIA1, PPFIA2 and PPFIA3, but not in PPFIA4. Bipartite nuclear localization signal was included within PFIH4 domain. PFIH2 domain was identical to ERM or Smc domain. The region spanning PFIH2-PFIH3 domains is the binding domain for KIF1A. The region spanning SAM1-SAM3 domains is the binding domain for LAR subfamily PTPases and PPFIBP (Liprin beta) family proteins. This is the first report on comprehensive characterization of PPFIA4 belonging to the PPFIA family of kinesin-cargo linkers.     

Identification and characterization of rat Ankrd6 gene in silico

WNT signals are transduced to the beta-catenin pathway or the planar cell polarity (PCP) pathway. Drosophila Frizzled (Fz), Starry night (Stan), Van Gogh (Vang), Prickle (Pk) and Diego (Dgo) are PCP signaling molecules. Human FZD1, FZD2, FZD3, FZD4, FZD5, FZD6, FZD7, FZD8, FZD9 and FZD10 are Fz homologs. Human CELSR1, CELSR2 and CELSR3 are Stan homologs. Human VANGL1 and VANGL2 are Vang homologs. Human PRICKLE1 and PRICKLE2 are Pk homologs. Human ANKRN6 is a Dgo homolog. Here, we identified and characterized rat Ankrd6 gene by using bioinformatics. Ankrd6 gene, consisting of 15 exons, was located within AC105547.5 genome sequence derived from rat chromosome 5q21. Rat Ankrd6 mRNA was expressed in corpus-striatum, eye, lung, and kidney. Rat Ankrd6 (714 aa) with six ankyrin (Ank) repeats and two coiled-coil regions showed 95.0, 84.2 and 53.4% total-amino-acid identity with mouse, human and zebrafish orthologs, respectively. Ser 340 of rat Ankrd6, conserved among mammalian Ankrd6 orthologs, was a protein kinase A (PKA) phosphotylation and 14-3-3 interaction site. Ank repeats are putative binding domains for Prickle1, Prickle2, Vangl1, and Vangl2. Central coiled-coil region is located within binding domain for Casein kinase I epsilon (CkIe). C-terminal coiled-coil region is located within binding domain for Axin1 and Axin2. Fourth to sixth Ank repeats of vertebrate Ankrd6 orthologs (codon 141-239) were highly conserved in Drosophila Dgo; however, two coiled-coil regions of vertebrate Ankrd6 orthologs were absent in Drosophila Dgo. Due to the molecular evolution, functions of vertebrate Ankrd6 orthologs were predicted to partially differ from those of Drosophila Dgo.     

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.     

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.     

Identification and characterization of the human FMN1 gene in silico

Mouse Formin (Fmn1) protein plays a key role in limb morphogenesis. Fmn1 is one of the actin regulators with scaffold function, interacting with Profilin, SRC, EMS1, FNBP1, FNBP2, FNBP3, FNBP4, WBP4 and alpha-catenin. Fmn1, Fmn2, FHOD1, FHOD3, GRID2IP and FHDC1 are non-FDD-type Formin homology proteins, while FMNL1, FMNL2, FMNL3, DIAPH1, DIAPH2, DIAPH3, DAAM1 and DAAM2 are FDD-type Formin homology proteins. Here, we identified the human FMN1 gene by using bioinformatics. The complete coding sequence of human FMN1 cDNA was determined by assembling AC055874.8 genome sequence (nucleotide position 178207-180073), AI040235 EST (complementary sequence for nucleotide position 331-156) and FLJ45135 cDNA (nucleotide position 319-3310). FMN1 isoform 1 (exons 1-18) and FMN isoform 2 (exons 1b and 3-18) were transcribed due to alternative splicing of the alternative promoter type. The FMN1 gene at human chromosome 15q13.3 was located between CKTSF1B1 (Gremlin) and RYR3 genes. The Xenopus fmn1 gene was identified within the Xenopus genome sequence CH216-24N20 (AC147835.1). The FMH1 domain (codon 1-120 of FMN1) and FMH2 domain (codon 683-835 of FMN1) were identified as novel regions conserved among human FMN1, mouse Fmn1, and Xenopus fmn1. The FMH2 domain was almost identical to the alpha-catenin binding domain of mouse Fmn1. Human FMN1 (1419 aa), showing 77.1% total amino-acid identity with mouse Fmn1, was found consisting of FMH1, FMH2, FH1 and FH2 domains. This is the first report on the identification and characterization of the human FMN1 gene as well as the FMH1 and FMH2 domains.     

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.     

Identification and characterization of ankyrin repeat and SOCS box-containing gene ASB15 in silico

The ASBs are a family of ankyrin-repeat proteins that contain a C-terminal SOCS box motif, which was first identified in the suppressor of cytokine signaling (SOCS) proteins. Here, we identified the ASB15 gene by using bio-informatics. Human ASB15 gene, consisting of 12 exons, was located within human genome sequences RP11-390E23 (AC006333.3). Complete coding sequence of human ASB15 cDNA was determined by FLJ43370 cDNA (AK125360), which was identified by using partial coding sequence of human ASB15 cDNA (AF403033) as a query. Human, chimpanzee, bovine, canine, and murine ASB15 showed 88-99% total-amino acid identity. N-terminal and central seven ankyrin repeats, and C-terminal SOCS box were identified within ASB15 protein.