The complex of Arl2-GTP and PDEdelta: from structure to function

Publisher Website
Google Scholar
Abstract
Arf‐like (Arl) proteins are close relatives of the Arf regulators of vesicular transport, but their function is unknown. Here, we present the crystal structure of full‐length Arl2‐GTP in complex with its effector PDEδ solved in two crystal forms (Protein Data Bank codes 1KSG, 1KSH and 1KSJ). Arl2 shows a dramatic conformational change from the GDP‐bound form, which suggests that it is reversibly membrane associated. PDEδ is structurally closely related to RhoGDI and contains a deep empty hydrophobic pocket. Further experiments show that H‐Ras, Rheb, Rho6 and Gαi1 interact with PDEδ and that, at least for H‐Ras, the intact C‐terminus is required. We suggest PDEδ to be a specific soluble transport factor for certain prenylated proteins and Arl2‐GTP a regulator of PDEδ‐mediated transport.