WDR44 is a member of the WD repeat family. The WD repeat is defined by four or more repeating units of a conserved core of approximately 40 amino acids ending with tryptophan-aspartic acid (WD). WD repeats may serve as sites of protein-protein interaction for adaptor proteins and facilitate multiprotein complex formation. WD-repeat domain 44 (WDR44) was originally identified as rabphilin-11, a protein isolated from bovine brain extracts and cloned from a rat brain cDNA library. Rabphilin-11 was found to bind GTP-Rab11 and proposed to localize to the Golgi and recycling endosomes suggesting a role in vesicle recycling. WDR44 contains seven WD (tryptophan-aspartate) repeat domains found in a number of proteins that function as adaptor molecules in signal transduction and cytoskeletal organization.