UNC119-binding protein family include human Macrophage immunometabolism regulator (also known as C5orf30) and its homologues from eukaryotes. C5orf30 may play a role in trafficking of proteins via its interaction with UNC119 and UNC119B cargo adapters. It may also play a role in ciliary membrane localisation [].
This entry represents protein unc-119 homologue A (UNC119) from vertebrates, also known as retinal protein 4 (RG4) [], and the homologue from Drosophila []. It is highly expressed in retinal photoreceptor inner segments and synaptic regions. Nevertheless, UNC119 has been detected in leukocytes (eosinophils), T-cells, lung fibroblasts, the adrenal glands, cerebellum and kidney. It interacts with several diverse proteins, such as Arf-like GTPases ARL2/ARL3 [, ]and the Ca2+-binding protein CaBP4 []. It has been shown to activate Src-type tyrosine kinases associated with the interleukin-5 receptor and the T-cell receptor. It is also required for G protein trafficking in sensory neurons [].Mutations in the UNC119 gene cause immunodeficiency 13 (IMD13), a rare and heterogeneous syndrome defined by a reproducible reduction in the CD4 T-lymphocyte count [].