InterPro domain: IPR040323

Proteins in this entry contain WD40 repeats. This entry includes mammalian EARP and GARP complex-interacting protein 1 (EIPR1 or TSSC1), which is a component of the endosomal retrieval machinery, binding to both the tethering complexes GARP and EARP. GARP participates in SNARE-dependent fusion of endosome-derived carriers with the trans-Golgi network, wheras EARP does the same for recycling endosomes [ 1 ]. Also included in this family is the EARP-interacting protein 1 from the nematode Caenorhabditis elegans, which trafficks cargo to the dense-core vesicle, a secretory organelle that mediates the regulated release of peptide hormones, growth factors, and biogenic amines and which originates from the trans-Golgi of neurons and neuroendocrine cells [ 2 ]. The WD repeat-containing protein DWA2 from Arabidopsis thaliana is also a member of this family. DWA2 is a component of an E3 ubiquitin-protein ligase complex that acts as negative regulator in abscisic acid signaling [ 3 ].

1. TSSC1 is novel component of the endosomal retrieval machinery. Mol. Biol. Cell 27, 2867-78
2. The EARP Complex and Its Interactor EIPR-1 Are Required for Cargo Sorting to Dense-Core Vesicles. PLoS Genet. 12, e1006074
3. DWA1 and DWA2, two Arabidopsis DWD protein components of CUL4-based E3 ligases, act together as negative regulators in ABA signal transduction. Plant Cell 22, 1716-32