title: Structural definition of the F-actin-binding THATCH domain from HIP1R.
abstract: Huntingtin-interacting protein-1 related (HIP1R) has a crucial protein-trafficking role, mediating associations between actin and clathrin-coated structures at the plasma membrane and trans-Golgi network. Here, we characterize the F-actin-binding region of HIP1R, termed the talin-HIP1/R/Sla2p actin-tethering C-terminal homology (THATCH) domain. The 1.9-A crystal structure of the human HIP1R THATCH core reveals a large sequence-conserved surface patch created primarily by residues from the third and fourth helices of a unique five-helix bundle. Point mutations of seven contiguous patch residues produced significant decreases in F-actin binding. We also show that THATCH domains have a conserved C-terminal latch capable of oligomerizing the core, thereby modulating F-actin engagement. Collectively, these results establish a framework for investigating the links between endocytosis and actin dynamics mediated by THATCH domain-containing proteins.
authors.affiliation: Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, Missouri 63110, USA.
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Brett
authors.forename: Valerie
authors.initials: V
authors.lastname: Legendre-Guillemin
authors.forename: Peter S
authors.initials: PS
authors.lastname: McPherson
authors.forename: Daved H
authors.initials: DH
authors.lastname: Fremont
mesh_terms: D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008840:Microfilament Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D040681:Structural Homology, Protein; D033921:Vesicular Transport Proteins
chemical_list: D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C489537:HIP1R protein, human; D008840:Microfilament Proteins; D033921:Vesicular Transport Proteins