Identification and characterization of human FMNL1, FMNL2 and FMNL3 genes in silico

FMNL (NM_005892.2) is a 5'-truncated partial cDNA encoding a Formin-homology protein related to DAAM1, DAAM2, DIAPH1 and DIAPH2. Here, we identified three members of FMNL gene family in the human genome by using bioinformatics. FMNL1 gene, corresponding to 5'-truncated KW-13 and FMNL cDNAs, was located within reference genomic contig NT_010748.9 (nucleotide position 100576-125849, forward orientation). FMNL2 gene, corresponding to KIAA1902 and FHOD2 cDNAs, was located within NT_005151.10 (nucleotide position 122465-436828, forward orientation). FMNL3 gene, corresponding to 5'-truncated DKFZp762B245 and KIAA2014 cDNAs, was located within NT_026397.10 (nucleotide position 209769-279037, reverse orientation). FMNL1, FMNL2 and FMNL3 genes encode A and B isoforms with the C-terminal divergence due to alternative splicing (cassette splicing of exon 26). FMNL1A (1100 aa), FMNL1B (1114 aa), FMNL2A (1087 aa), FMNL2B (1093 aa), FMNL3A (1028 aa) and FMNL3B (1027 aa) consist of FDD, FH1 and FH2 domains. Total amino-acid identity were as follows: FMNL1A vs. FMNL2A, 59.3%; FMNL1A vs. FMNL3A, 56.1%; FMNL2A vs. FMNL3A, 68.6%. FMNL1 gene was mapped to human chromosome 17q21. FMNL2 gene was linked to FNBP3/HYPA gene on chromosome 2q23.3, while FMNL3 gene was linked to FNBP3L/HYPC gene on chromosome 12q13. FMNL1 mRNA was expressed in natural killer cells, Burkitt lymphoma, pancreatic cancer, prostate cancer, and lung large cell carcinoma, FMNL2 mRNA in several normal tissues, diffuse-type gastric cancer, breast cancer, chondrosarcoma, melanoma, and glioblastoma, and FMNL3 mRNA in gastric cancer. FMNL1, FMNL2 and FMNL3 might be implicated in polarity control, invasion, migration, or metastasis through regulation of the Rho-related signaling pathway.