The role of transportin-1 in the ciliary targeting of membrane proteins
Date of Issue2016-05-15
School of Biological Sciences
The sensory functions of cilia are dependent on the enrichment of ciliary resident proteins. While it is known that ciliary targeting signals (CTSs) specifically target ciliary proteins to cilia, it is less clear how CTSs facilitate the entry and retention of ciliary residents at molecular level. We found that non-ciliary membrane reporters could passively diffuse to cilia via the lateral transport pathway and the translocation of membrane reporters through ciliary diffusion barrier could be facilitated by importin binding motifs/domains. We further discovered that a novel ternary complex, comprising Rab8, TNPO1 and CTS, could be assembled or disassembled under the guanine nucleotide exchange of Rab8. Our study suggests a novel mechanism in which Rab8/TNPO1/CTS complex mediates selective entry and retention of cargos within cilia.