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The NECAP PHear domain increases clathrin accessory protein binding potential
Author(s) -
Ritter Brigitte,
Denisov Alexei Yu,
Philie Jacynthe,
Allaire Patrick D,
LegendreGuillemin Valerie,
Zylbergold Peter,
Gehring Kalle,
McPherson Peter S
Publication year - 2007
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601836
Subject(s) - biology , clathrin , plasma protein binding , biophysics , microbiology and biotechnology , biochemistry , endocytosis , receptor
AP‐2 is a key regulator of the endocytic protein machinery driving clathrin‐coated vesicle (CCV) formation. One critical function, mediated primarily by the AP‐2 α‐ear, is the recruitment of accessory proteins. NECAPs are α‐ear‐binding proteins that enrich on CCVs. Here, we have solved the structure of the conserved N‐terminal region of NECAP 1, revealing a unique module in the pleckstrin homology (PH) domain superfamily, which we named the PHear domain. The PHear domain binds accessory proteins bearing FxDxF motifs, which were previously thought to bind exclusively to the AP‐2 α‐ear. Structural analysis of the PHear domain reveals the molecular surface for FxDxF motif binding, which was confirmed by site‐directed mutagenesis. The reciprocal analysis of the FxDxF motif in amphiphysin I identified distinct binding requirements for binding to the α‐ear and PHear domain. We show that NECAP knockdown compromises transferrin uptake and establish a functional role for NECAPs in clathrin‐mediated endocytosis. Our data uncover a striking convergence of two evolutionarily and structurally distinct modules to recognize a common peptide motif and promote efficient endocytosis.