Molecular cloning and characterization of Strabismus 2 (STB2).
WNT signaling pathway is implicated in carcinogenesis and embryogenesis. WNT signal is transduced to the beta-catenin - TCF pathway, the JNK pathway, or the Ca2+-releasing pathway through seven-transmembrane-type WNT receptors encoded by Frizzled (FZD) genes. Xenopus Strabismus (Stbm) is a tetra-spanning transmembrane protein interacting with Dishevelled, and is a negative regulator of the WNT - beta-catenin - TCF signaling pathway. STB1/KIAA1215/VANGL2 is a human orthologue of Xenopus Stbm (90.6% total-amino-acid identity). Here, STB2/VANGL1 gene fragments were identified in human genome draft sequences by using bioinformatics, and STB2 cDNAs were isolated by using cDNA-PCR. STB2 gene consisted of at lest 7 exons, and encoded a 524-amino-acid protein with 4 transmembrane domains and the C-terminal Ser/Thr-X-Val motif. Human STB2 was homologous to human STB1 (73.1% total-amino-acid identity) and Xenopus Stbm (72.7% total-amino-acid identity). STB2 gene was clustered with Calsequestrin 2 (CASQ2) gene in tail-to-tail manner (interval less than 5.0 kb), and CASQ2 gene is mapped to human chromosome 1p11-p13.3 or linked to human chromosome 1p13-p21. STB2 mRNAs of 4.8- and 6.8-kb in size were expressed almost ubiquitously in various normal tissues. STB2 mRNA was significantly up-regulated in gastric cancer cell lines MKN28, MKN74, pancreatic cancer cell lines BxPC-3, PSN-1 and Hs766T. On the other hand, STB2 mRNA was significantly down-regulated in a pancreatic cancer cell line AsPC-1. This is the first report on molecular cloning and characterization of STB2.
Katoh
Masaru
M
Genetics and Cell Biology Section, Genetics Division, National Cancer Center Research Institute, Tokyo 104-0045, Japan. mkatoh@ncc.go.jp
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins; D002878:Chromosomes, Human, Pair 1 / Q000648:ultrastructure; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D015536:Down-Regulation; D005091:Exons; D015894:Genome, Human; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D010455:Peptides / Q000378:metabolism; D011061:Poly A; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured; D015854:Up-Regulation; D014981:Xenopus
D002352:Carrier Proteins; D018076:DNA, Complementary; D008565:Membrane Proteins; D010455:Peptides; D012333:RNA, Messenger; C488287:VANGL1 protein, human; D011061:Poly A; D012313:RNA