Molecular cloning and characterization of human Frizzled-4 on chromosome 11q14-q21

The WNT receptors, encoded by the Frizzled genes, are implicated in a varie ty of cellular processes such as cell fate determination, cell polarity con trol, and malignant transformation. Human Frizzled-4 (FZD4) cDNAs have been cloned and characterized. FZD4 spans a total of 7392 nucleotides and encod es a 537-amino-acid protein with the N-terminal cysteine-rich domain, seven transmembrane domains, and the C-terminal S/T-X-V motif, The FZD4 mRNA of 7.7 kb in size were detected almost ubiquitously in normal human tissues an d larger amounts in fetal kidney, adult heart, skeletal muscle, and ovary. Among cancer cell lines, the FZD4 mRNA level was higher in HeLa S3. The FZD 4 gene has been mapped to human chromosome 11q14-q21. FZD4 is homologous to FZD9 and FZD10, and overall amino acid identity is as follows: FZD4 vs FZD 9, 51.6%; FZD4 vs FZD10, 51.2%; FZD9 vs FZD10, 65.7%. FZD4 consists of two exons, while FZD9 and FZD10 consist of a single exon, FZD4 might belong to rather the independent FZD subfamily than the FZD9-FZD10 subfamily. (C) 199 9 Academic Press.