Molecular cloning and initial characterization of the MG61/PORC gene, the human homologue of the Drosophila segment polarity gene Porcupine

• Published in: Gene 2002-04, Vol.288 (1), p.147-157
• Main Authors: Caricasole, Andrea, Ferraro, Teresa, Rimland, Joseph M., Terstappen, Georg C.
• Format: Article
• Language: English
• Subjects: Acyltransferases; Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Blotting, Northern; Cloning, Molecular; Computational Biology; DNA, Complementary - chemistry; DNA, Complementary - genetics; Drosophila - genetics; Drosophila Proteins; Exons; Expression pattern; Female; Functional analysis; Gene Expression; Genes - genetics; Humans; Introns; Isoforms; Male; Membrane Proteins - genetics; Mice; Molecular Sequence Data; PC12 Cells; Protein Isoforms - genetics; Rats; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; TaqMan; Tumor Cells, Cultured; Wnt (wingless and int homologue processing)
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/S0378-1119(02)00467-5

Insect and vertebrate Porcupine genes encode multi-pass endoplasmic reticulum proteins involved in the processing of Wnt (wingless and int homologue) proteins, a class of secreted glycoprotein factors homologous to the Drosophila melanogaster segment polarity gene Wingless ( Wg). Here we report the cloning of cDNAs encoding the human homologue of the Drosophila gene Porcupine ( Porc), the characterization of its genomic structure and the quantitative analysis of its expression in a comprehensive panel of human tissues. The human Porcupine locus ( MG61/PORC) spans 15 exons over approximately 12 kb of genomic sequence on Xp11.23. Real-time quantitative expression analysis reveals that MG61/PORC transcripts are expressed in multiple tissues, but are particularly abundant in the brain. Like its mouse and Xenopus homologues, MG61/PORC encodes four protein isoforms (A–D) generated through alternative splicing and expressed in a tissue-specific fashion. Finally, we present evidence indicating that MG61/PORC can influence the activity of a human Wnt7A expression construct in a T-cell factor-responsive reporter assay.