Download MendeleyStructural Insight Into the Escrt-I/-II Link and its Role in Mvb Trafficking.
Gill, D.J., Teo, H., Sun, J., Perisic, O., Veprintsev, D.B., Emr, S.D., Williams, R.L.(2007) EMBO J 26: 600
- PubMed: 17215868
- DOI: https://doi.org/10.1038/sj.emboj.7601501
- PubMed Abstract:
ESCRT (endosomal sorting complex required for transport) complexes orchestrate efficient sorting of ubiquitinated transmembrane receptors to lysosomes via multivesicular bodies (MVBs). Yeast ESCRT-I and ESCRT-II interact directly in vitro; however, this association is not detected in yeast cytosol. To gain understanding of the molecular mechanisms of this link, we have characterised the ESCRT-I/-II supercomplex and determined the crystal structure of its interface. The link is formed by the vacuolar protein sorting (Vps)28 C-terminus (ESCRT-I) binding with nanomolar affinity to the Vps36-NZF-N zinc-finger domain (ESCRT-II). A hydrophobic patch on the Vps28-CT four-helix bundle contacts the hydrophobic knuckles of Vps36-NZF-N. Mutation of the ESCRT-I/-II link results in a cargo-sorting defect in yeast. Interestingly, the two Vps36 NZF domains, NZF-N and NZF-C, despite having the same core fold, use distinct surfaces to bind ESCRT-I or ubiquitinated cargo. We also show that a new component of ESCRT-I, Mvb12 (YGR206W), engages ESCRT-I directly with nanomolar affinity to form a 1:1:1:1 heterotetramer. Mvb12 does not affect the affinity of ESCRT-I for ESCRT-II in vitro. Our data suggest a complex regulatory mechanism for the ESCRT-I/-II link in yeast.
Organizational Affiliation:
MRC Laboratory of Molecular Biology, Medical Research Council Centre, Cambridge, UK. djg38@mrc-lmb.cam.ac.uk
