title: RICH-1 has a BIN/Amphiphysin/Rvsp domain responsible for binding to membrane lipids and tubulation of liposomes.
abstract: RhoGAP interacting with CIP4 homologs-1 (RICH-1) was previously found in a yeast two-hybrid screen for proteins interacting with the SH3 domain of the Cdc42-interacting protein 4 (CIP4). RICH-1 was shown to be a RhoGAP for Cdc42 and Rac. In this study, we show that the BIN/Amphiphysin/Rvsp (BAR) domain in RICH-1 confers binding to membrane lipids, and has the potential to deform spherical liposomes into tubes. In accordance with previous findings for the BAR domains in endophilin and amphiphysin, RICH-1-induced tubes appeared striated. We propose that these striated structures are formed by oligomerization of RICH-1 through a putative coiled-coil region within the BAR domain. In support of this notion, we show that RICH-1 forms oligomers in the presence of the chemical cross-linker BS3. These results point to an involvement of RICH-1 in membrane deformation events.
authors.affiliation: Ludwig Institute for Cancer Research, Box 595, Biomedical Center, 751 24 Uppsala, Sweden.
authors.forename: Ninna
authors.initials: N
authors.lastname: Richnau
authors.forename: Asa
authors.initials: A
authors.lastname: Fransson
authors.forename: Khashayar
authors.initials: K
authors.lastname: Farsad
authors.forename: Pontus
authors.initials: P
authors.lastname: Aspenström
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D042783:Endothelial Cells / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000737:chemistry* / Q000378:metabolism*; D008081:Liposomes / Q000378:metabolism*; D008560:Membrane Fluidity / Q000502:physiology*; D008563:Membrane Lipids / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D013552:Swine; D014018:Tissue Distribution
chemical_list: D020690:GTPase-Activating Proteins; D008081:Liposomes; D008563:Membrane Lipids; D009419:Nerve Tissue Proteins; C075637:amphiphysin