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Midbody targeting of the ESCRT machinery by a noncanonical coiled coil in CEP55
Author(s) -
Lee Hyung Ho,
Elia Natalie,
Ghirlando Rodolfo,
LippincottSchwartz Jennifer,
Hurley James H.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.864.1
Subject(s) - escrt , cytokinesis , midbody , tsg101 , coiled coil , microbiology and biotechnology , chemistry , endosome , heterotetramer , biology , protein subunit , cell division , biochemistry , cell , intracellular , gene , microrna , microvesicles
The ESCRT (endosomal sorting complex required for transport) machinery is required for the scission of membrane necks in processes including the budding of HIV‐1 and cytokinesis. An essential step in cytokinesis is recruitment of the ESCRT‐I complex and the ESCRT‐associated protein ALIX to the midbody (the structure that tethers two daughter cells) by the protein CEP55. Biochemical experiments show that peptides from ALIX and the ESCRT‐I subunit TSG101 compete for binding to the ESCRT and ALIX‐binding region (EABR) of CEP55. We solved the crystal structure of EABR bound to an ALIX peptide at a resolution of 2.0 angstroms. The structure shows that EABR forms an aberrant dimeric parallel coiled coil. Bulky and charged residues at the interface of the two central heptad repeats create asymmetry and a single binding site for an ALIX or TSG101 peptide. Both ALIX and ESCRT‐I are required for cytokinesis, which suggests that multiple CEP55 dimers are required for function.