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We have used cryo-electron microscopy to determine the 3D structure of a complex of clathrin, auxilin^401-910 and Hsc70 trapped early in the recruitment of Hsc70 to the clathrin cage. We observed that Hsc70 bound asymmetrically to the clathrin vertex and induced structural changes close to the location of clathrin light chains on the outermost edge of the cage. Clathrin disassembly assays using light scattering suggested that loss of clathrin light chains reduced the efficiency with which auxilin could facilitate disassembly.

The lectin galectin-3 is secreted into the apical medium of polarized MDCK cells. Once in the medium galectin-3 can be endocytosed via caveolin/flotillin-positive patches for entry into early endosomes. This process is pH dependent. Within endosomal organelles, most likely recycling endosomes, the lectin associates with newly synthesized non-raft associated apical cargo and assists in its apical targeting. Following release at the apical membrane galectin-3 can reenter the cell in another round of recycling.

Small GTPase Rab Rab27 is widely conserved in metazoan, and two Rab27 isoforms, Rab27A and Rab27B, are present in vertebrates. Although Rab27A and Rab27B were initially thought to function redundantly by sharing common Rab27 effectors in secretory pathways, recent evidence has indicated that by interacting with different Rab27 effectors they play different roles in special types of secretion. In this review article I describe the current state of our understating of the functions of Rab27 effectors in secretory pathways.

This study reports a global analysis of the localization and essentiality of the repertoire of the DHHC family of protein S-acyl transferases in Toxoplasma gondii and Plasmodium berghei. Some of the essential DHHCs are located to specialized organelles and conserved across the phylum of Apicomplexa. DiCre-dependent excision of TgDHHC7 gene leads to the mislocalization of the acylated protein, TgARO, impacting on the apical positioning of rhoptries and consequently on host cell invasion but not on parasite egress from infected cells.

Recycling is a limiting step for receptor-mediated endocytosis. We here show that class III PI3K is the key isoform involved, based on differential pharmacological inhibition (substractive approach) and PI-3P sequestration by overexpressed GFP-(FYVE)x2 in cultured kidney epithelial cells, as well as conditional PI3KIII/ Vps34 KO in developing mice kidneys. Acute reversal of PI3K inhibition induced a spectacular burst of recycling tubules that recruited dynamin-GFP and depended on its GTPase activity. This simple procedure may help further dissect recycling machineries.

Ezrin and moesin depletion leads to reduced binding of Shiga toxin (Stx), reduced retrograde Stx transport to the Golgi and protection from Stx toxicity. Endocytosed toxin seems to be arrested in hybrid compartments between early and late endosomal stages unable to recruit the retromer complex. Vps11 depletion on the other hand, leads to increased retrograde Stx transport. Finally, ezrin and moesin knockdown does not affect retrograde transport of ricin.