RUN And FYVE Domain Containing Protein 1 (RUFY1)

ETK phosphorylated RUFY1 on tyr281 and tyr292 in the linker region between the coiled-coil domains, and mutation of tyr281 and tyr292 abolished interaction with the SH2 domain of ETK and interfered with targeting of RUFY1 to endosomes. second coiled-coil domain in RUFY1 was also required for endosomal targeting. The deduced 600-amino acid protein has an N-terminal RUN domain, 2 central coiled-coil domains, and a C-terminal FYVE domain containing 2 zinc-binding sites and an SH3 domain recognition motif (PxxPxP). Northern blot analysis detected RUFY1 expression in brain, kidney, liver, lung, placenta, and testis. The mouse RUFY1 homolog, Rabip4, showed a different tissue distribution. Fluorescence-tagged RUFY1 colocalized with an endosomal marker protein in transfected COS-1 cells.