High impact information on RUFY1

• In this study, we explored the role of Rabip4 and Rabip4', two Rab4 effector proteins, in migration of NIH 3T3 fibroblasts [1].
• The Rab4A Effector Protein Rabip4 Is Involved in Migration of NIH 3T3 Fibroblasts [1].
• The RUFY gene family (RUFY1 and RUFY2) contains an N-terminal RUN domain and a C-terminal FYVE domain with two coiled-coil domains in-between [2].
• The RUFY1 mutant lacking the phosphorylation sites failed to go to the endosomes [2].
• Interestingly, the FYVE domain of RUFY1 is targeted to the plasma membrane through an interaction between its proline-rich motif and the SH3 domain of Etk or possibly some other membrane-associated SH3 domain-containing protein(s), whereas the lipid binding activity of the FYVE domain is not required [2].

Biological context of RUFY1

• Our data suggest that Etk may be involved in regulation of endocytosis through its interaction with an endosomal protein RUFY1 [2].

Anatomical context of RUFY1

• Although the FYVE finger domain specifically bound phosphatidylinositol 3-phosphate and was necessary for the function of Rabip4, it was not sufficient for the protein association with membranes [3].

Associations of RUFY1 with chemical compounds

• Rabip4-(1-212) was totally Triton X-100-insoluble, and confocal microscopic examination showed that it labeled not only the endosomes, positive for Rabip4, but also a filamentous network with a honeycomb appearance [3].

Physical interactions of RUFY1

• In agreement with this, we found that rabip4' colocalized with the two GTPases on early endosomes and bound specifically and simultaneously to the GTP form of both rab4 and rab5 [4].

Other interactions of RUFY1

• We conclude that rabip4' may coordinate the activities of rab4 and rab5, regulating membrane dynamics in the early endosomal system [4].
• The Triton X-100-insoluble fraction that contains Rabip4 did not correspond to the caveolin or glycosylphosphatidylinositol-enriched lipid rafts [3].

References