The mouse Arhgef6 gene: cDNA sequence, expression analysis, and chromosome assignment

Mutations in ARHGEF6, encoding a guanine nucleotide exchange factor for Rho GTPases, have been shown to cause X-chromosomal non-specific mental retardation (MRX) in human. Here we report the identification and characterization of the orthologous mouse gene, Arhgef6. The gene transcript of approximately 4.4 kb is present in various mouse tissues indicating ubiquitous expression as found for human ARHGEF6. The open reading frame encodes a polypeptide of 771 amino acids with high homology to human ARHGEF6. The structural motifs of both proteins are conserved including an N-terminal CH domain, followed by an SH3 domain, and a tandem organization of the DH and PH domains. Analysis of the temporal expression pattern revealed that Arhgef6 is strongly expressed in the very early embryo and somewhat less in later stages. A genomic cosmid clone containing Arhgef6 exons 1 and 2 has been isolated and used for mapping the gene on the mouse X chromosome.