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Structural basis for the Golgi association by the pleckstrin homology domain of the ceramide trafficking protein (CERT).

Abstract

Ceramide transport from the endoplasmic reticulum to the Golgi apparatus is crucial in sphingolipid biosynthesis, and the process relies on the ceramide trafficking protein (CERT), which contains pleckstrin homology (PH) and StAR-related lipid transfer domains. The CERT PH domain specifically recognizes phosphatidylinositol 4-monophosphate (PtdIns(4)P), a characteristic phosphoinositide in the Golgi membrane, and is indispensable for the endoplasmic reticulum-to-Golgi transport of ceramide by CERT. In this study, we determined the three-dimensional structure of the CERT PH domain by using solution NMR techniques. The structure revealed the presence of a characteristic basic groove near the canonical PtdIns(4)P recognition site. An extensive interaction study using NMR and other biophysical techniques revealed that the basic groove coordinates the CERT PH domain for efficient PtdIns(4)P recognition and localization in the Golgi apparatus. The notion was also supported by Golgi mislocalization of the CERT mutants in living cells. The distinctive binding modes reflect the functions of PH domains, as the basic groove is conserved only in the PH domains involved with the PtdIns(4)P-dependent lipid transport activity but not in those with the signal transduction activity.

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  • Publisher Full Text

    • Authors

    Sugiki T, Takeuchi K, Yamaji T, Takano T, Tokunaga Y, Kumagai K, Hanada K, Takahashi H, Shimada I

    Institution

    Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan.

    Source

    The Journal of biological chemistry 287:40 2012 Sep 28 pg 33706-18

    MeSH

    Amino Acid Motifs
    Amino Acid Sequence
    Endoplasmic Reticulum
    Golgi Apparatus
    Humans
    Kinetics
    Lipids
    Liposomes
    Magnetic Resonance Spectroscopy
    Models, Molecular
    Molecular Conformation
    Molecular Sequence Data
    Mutagenesis, Site-Directed
    Phosphatidylinositols
    Protein Conformation
    Protein Structure, Tertiary
    Protein-Serine-Threonine Kinases
    Sequence Homology, Amino Acid
    Surface Plasmon Resonance

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22869376