RhoGEFs belongs to regulator of G-protein signaling (RGS) domain-containing RhoGEFs that are RhoA-selective and directly activated by the Galpha12/13 family of heterotrimeric G proteins. The members here all contain Dbl homology (DH)-PH domains. In addition some members contain N-terminal C1 (Protein kinase C conserved region 1) domains, PDZ (also called DHR/Dlg homologous regions) domains, ANK (ankyrin) domains, and RGS (Regulator of G-protein signalling) domains or C-terminal ATP-synthase B subunit. The DH-PH domains bind and catalyze the exchange of GDP for GTP on RhoA. RhoGEF2/Rho guanine nucleotide exchange factor 2, p114RhoGEF/p114 Rho guanine nucleotide exchange factor, p115RhoGEF, p190RhoGEF, PRG/PDZ Rho guanine nucleotide exchange factor, RhoGEF 11, RhoGEF 12, RhoGEF 18, AKAP13/A-kinase anchoring protein 13, and LARG/Leukemia-associated Rho guanine nucleotide exchange factor are included in this CD. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.
Jiyao W et al.(2023). "The conserved domain database in 2023.",