protein kinase C conserved region 1 (C1 domain) found in uncharacterized Rho guanine nucleotide exchange factor 18 (ARHGEF18)-like proteins
The family includes a group of uncharacterized proteins that show high sequence similarity to vertebrate ARHGEF18, which is also called 114 kDa Rho-specific guanine nucleotide exchange factor (p114-Rho-GEF), p114RhoGEF, or septin-associated RhoGEF (SA-RhoGEF). ARHGEF18 acts as guanine nucleotide exchange factor (GEF) for RhoA GTPases. Its activation induces formation of actin stress fibers. ARHGEF18 also acts as a GEF for RAC1, inducing production of reactive oxygen species (ROS). Members of this family contain C1, RhoGEF or Dbl-homologous (DH), and Pleckstrin Homology (PH) domains, as well as a DUF5401 domain. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.