TBC1 Domain Family, Member 10A (TBC1D10A)

EPI64 gene encodes a deduced 508-amino acid protein ending in the amino acids DTYL, and a TBC/rabGAP domain. Western blot analysis of mouse and human tissues revealed that EPI64 protein is present in most tissues and human cell lines, with the exception of skeletal muscle, and is enriched in placental microvilli. GST-fusion experiments showed that wildtype EPI64 binds to the PDZ domains of EBP50 and E3KARP, whereas mutant EPI64 with an additional alanine in the extreme C terminus does not. Fluorescence microscopy demonstrated that EPI64 is enriched in the syncytiotrophoblast region of human placenta, which contains abundant actin-rich microvilli. In human JEG-3 cells, EPI64 specifically localized to the surface microvilli, where it colocalized with EBP50 and showed significant overlap with ezrin and cortical F-actin.