Yeast Ivy1p Is a Putative I-BAR-domain Protein with pH-sensitive Filament Forming Ability <i>in vitro</i>

Access this Article

Author(s)

    • Itoh Yuzuru Itoh Yuzuru
    • Laboratory of Membrane and Cytoskeleton Dynamics, Institute of Molecular and Cellular Biosciences, The University of Tokyo
    • Kida Kazuki Kida Kazuki
    • Laboratory of Molecular Medicine and Cell Biology, Graduate School of Biosciences, Nara Institute of Science and Technology
    • Hanawa-Suetsugu Kyoko Hanawa-Suetsugu Kyoko
    • Laboratory of Membrane and Cytoskeleton Dynamics, Institute of Molecular and Cellular Biosciences, The University of Tokyo|Laboratory of Molecular Medicine and Cell Biology, Graduate School of Biosciences, Nara Institute of Science and Technology
    • Suetsugu Shiro Suetsugu Shiro
    • Laboratory of Membrane and Cytoskeleton Dynamics, Institute of Molecular and Cellular Biosciences, The University of Tokyo|Laboratory of Molecular Medicine and Cell Biology, Graduate School of Biosciences, Nara Institute of Science and Technology

Abstract

Bin-Amphiphysin-Rvs161/167 (BAR) domains mold lipid bilayer membranes into tubules, by forming a spiral polymer on the membrane. Most BAR domains are thought to be involved in forming membrane invaginations through their concave membrane binding surfaces, whereas some members have convex membrane binding surfaces, and thereby mold membranes into protrusions. The BAR domains with a convex surface form a subtype called the inverse BAR (I-BAR) domain or IRSp53-MIM-homology domain (IMD). Although the mammalian I-BAR domains have been studied, those from other organisms remain elusive. Here, we found putative I-BAR domains in Fungi and animal-like unicellular organisms. The fungal protein containing the putative I-BAR-domain is known as Ivy1p in yeast, and is reportedly localized in the vacuole. The phylogenetic analysis of the I-BAR domains revealed that the fungal I-BAR-domain containing proteins comprise a distinct group from those containing IRSp53 or MIM. Importantly, Ivy1p formed a polymer with a diameter of approximately 20 nm <i>in vitro</i>, without a lipid membrane. The filaments were formed at neutral pH, but disassembled when pH was reverted to basic. Moreover, Ivy1p and the I-BAR domain expressed in mammalian HeLa cells was localized at a vacuole-like structure as filaments as revealed by super-resolved microscopy. These data indicate the pH-sensitive polymer forming ability and the functional conservation of Ivy1p in eukaryotic cells.

Journal

  • Cell Structure and Function

    Cell Structure and Function 41(1), 1-11, 2016

    Japan Society for Cell Biology

Codes

  • NII Article ID (NAID)
    130005126757
  • NII NACSIS-CAT ID (NCID)
    AA0060007X
  • Text Lang
    ENG
  • ISSN
    0386-7196
  • NDL Article ID
    028100135
  • NDL Call No.
    Z53-V38
  • Data Source
    NDL  J-STAGE 
Page Top