Poster Presentation 2014 International Biophysics Congress

Structural studies on sorting nexins (#644)

Jinxin Xu 1 , Tingting Xu 1 , Jinsong Liu 1
  1. Guangzhou Institutes of Biomedicine and Health, Guangzhou, China

Sorting nexins (SNXs) are a family of proteins that involved in diverse intracellular endosomal trafficking pathways. They all contain a PX (phox-homology) domain. The PX domain, via binding to certain phosphoinositide lipids, is responsible for membrane attachment to organelles of the endosomal system. The PX domain mostly binds to PtdIns3P, although other specificities have been reported for a few SNXs.

It was previously reported that over expression of SNX10 could induce the formation of giant vacuoles in mammalian cells. Furthermore, an SNX10/V-ATPase regulated vesicular trafficking pathway was identified to be crucial during early embryonic development. More recently, several mutations in SNX10 have been linked to osteopetrosis. Meanwhile, SNX11, a close homologue of SNX10, was found to be able to inhibit SNX10-induced vacuolation. We recently reported the crystal structure of SNX11 and proposed a novel extended PX domain.1  Our study on SNX10 confirmed this finding. We also observed different specificities for phosphoinositide lipids between SNX10 and SNX11. These findings will further our understanding on SNXs’ roles in endosomal trafficking. 

  1. Xu, J., T. Xu, B. Wu, Y. Ye, X. You, X. Shu, D. Pei and J. Liu (2013). "Structure of sorting nexin 11 (SNX11) reveals a novel extended phox homology (PX) domain critical for inhibition of SNX10-induced vacuolation." J Biol Chem 288(23): 16598-16605.