Planned Member


Taroh Kinoshita
Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University

Investigation of intra-Golgi zone for maturation and transport of GPI-anchored proteins

Research abstract

Glycosylphosphatidylinositols (GPI) are glycolipids that are used as membrane anchors of many cell surface proteins in eukaryotic cells. At least 150 different human proteins are GPI-anchored proteins (GPI-APs). GPI-anchor confers proteins with particular characteristics such as association with lipid microdomains, shedding after cleavage within GPI and apical transport in polarized cells. GPI is essential for life as shown by knockout of a gene involved in GPI biosynthesis that caused early death of mouse embryos. In recent years, taking advantage of whole exome sequencing, individuals who have inherited partial loss-of-function mutations in genes involved in GPI biosynthesis have been found. Clinical symptoms of these individuals indicate roles of GPI-APs in various organs and tissues. Loss-of-function mutations in genes involved in maturation of GPI-APs also cause various phenotypes, indicating that not only amounts but also structure of GPI is critical for human health.
Recent studies demonstrated variations in behaviors of various GPI-APs and possible contributions of side-chain modifications. However, how GPI side-chain modifications are regulated is only partially understood. Because molecular basis of structural variation in GPI side-chains is critical for biology and medicine of GPI-APs, our current study is focused on genes involved in GPI side-chain modifications. In many GPI-APs, N-acetylgalactosamine (GalNAc) is linked to the first mannose in β4 linkage as a side-chain. The GalNAc side-chain can be elongated byβ3 linked galactose (Gal) and further by sialic acid (Figure). Physiological roles of this GalNAc side-chain has been unclear because genes involved have not been identified. Extents of structural variation of the GalNAc side-chains in GPI-APs and tissues are not well understood either. Intra Golgi localization of relevant enzymes is not known.
We recently identified gene encoding Golgi-residentβ4 GalNAc transferase that mediates transfer of GalNAc to the first mannose (Hirata et al, 2018, Nat Commun). We termed the gene PGAP4 for Post GPI Attachment to Proteins 4. We now work on cloning b3Gal transferase that mediates GalNAc side-chain elongation by Gal. A goal in this joint study is to determine where GPI-AP maturation (GPI fatty acid remodeling and side-chain modification) occurs in the Golgi and whether it occurs in a specific zone.


Original papers

  1. Wang, Y., Hirata, T., Maeda, Y., Murakami, Y., Fujita, M., and Kinoshita, T. (2019) Free, unlinked glycosylphosphatidylinositols on mammalian cell surfaces revisited. J. Biol. Chem., 294:5038-5049.

  2. Murakami, Y.,* Nguyen*, T. T. M., Baratang, N., Raju, P. K., Knaus, A., Ellard, S., Jones, G., Lace, B., Rousseau, J., Ajeawung, N. F., Kamei, A., Minase, G., Akasaka, M., Araya, N., Koshimizu, E., van den Ende, J., Erger, F., Altmüller, J., Krumina, Z., Strautmanis, J., Inashkina, I., Stavusis, J., El-Gharbawy, A., Sebastian, J., Dua Puri, R., Kulshrestha, S., Verma, I. C., Maier, E. M., Haack, T., Israni, A., Baptista, J., Gunning, A., Rosenfeld, J. A., Liu, P., Joosten, M., Rocha, M. E., Hashem, M. O., Aldhalaan, H. M., Alkuraya, F. S., Miyatake, S., Matsumoto, N., Krawitz, P., Rossignol, E., Kinoshita, T., and Campeau, P. M. (2019) Mutations in PIGB cause an inherited GPI biosynthesis defect with an axonal neuropathy and metabolic abnormality in severe cases. Am. J. Hum. Genet., 105:384-394.

  3. Hoechsmann, B.*, Murakami, Y. *, Osato, M. *, Knaus, A., Kawamoto, M., Inoue, N., Hirata, T., Murata, S., Anliker, M., Eggermann, T., Jaeger, M., Floettmann, R., Hoellein, A., Murase, S., Ueda, Y., Nishimura, J., Kanakura, Y., Kohara, N., Schrezenmeier, H.+, Krawitz, P. M.+, and Kinoshita, T. + (2019) Complement and inflammasome overactivation mediates paroxysmal nocturnal hemoglobinuria with autoinflammation. J. Clin. Invest.,129:5123-5136. doi: 10.1172/JCI123501

  4. Nuclear envelope localization of PIG-B is essential for GPI-anchor synthesis in Drosophila.
    Yamamoto-Hino.M., Katsumata, E., Suzuki, E., Maeda, Y., Kinoshita, T. and Goto, S.
    J. Cell Sci., 131, jcs218024 (2018)
    DOI: 10.1242/jcs.218024
  5. Mogami, Y., Suzuki, Y., Murakami, Y., Ikeda, T., Kimura, S., Yanagihara, K., Okamoto, N., and Kinoshita, T. (2018) Early infancy-onset stimulation-induced myoclonic seizures in three siblings with inherited glycosylphosphatidylinositol (GPI) anchor deficiency. Epileptic Disord., 20:42-50.

  6. Pagnamenta, A. T. *, Murakami, Y. *, Anzilotti, C., Titheradge, H., Oates, A. J., Morton, J., The DDD Study, Kinoshita, T.+, Kini, U.+, and Taylor, J. C.+. (2018) A homozygous variant disrupting the PIGH start-codon is associated with developmental delay, epilepsy and microcephaly. Hum. Mutat., 39:822-826. (* and +, equal contribution)

  7. Yoko-o, T., Umemura, M., Komatsuzaki, A., Ikeda, K., Ichikawa, D., Takase, K., Kanzawa, N., Saito, K., Kinoshita, T., Taguchi, R., and Jigami, Y. (2018) Lipid moiety of glycosylphosphatidylinositol-anchored proteins contributes to the determination of their final destination in yeast. Genes Cells, 23:880-892.
  8. Kawamoto, M., Murakami, Y., Kinoshita, T., and Kohara, N. (2018) Recurrent aseptic meningitis with PIGT mutations: a novel pathogenesis of recurrent meningitis successfully treated by eculizumab. BMJ Case Rep., pii: bcr-2018-225910.

  9. Nguyen, T. T. M., Murakami, Y., Wigby, K. M., Baratang, N. V., St-Denis, A., Rosenfeld, J. A., Laniewski, S. C., Jones, J., Iglesias, A. D., Jones, M. C., Masser-Frye, D., Scheuerle, A. E., Taft, R. J., Le Deist, F., Thompson, M., Kinoshita, T., and Campeau, P. M. (2018) Mutations in PIGS, encoding a GPI transamidase, cause a neurological syndrome ranging from fetal akinesia to epileptic encephalopathy. Am. J. Hum. Genet., 103:602-611.

  10. Yamamoto-Hino, M., Katsumata, E., Suzuki, E., Maeda, Y., Kinoshita, T., and Goto, S. (2018) Nuclear envelope localization of PIG-B is essential for GPI anchor synthesis in Drosophila. J. Cell Sci., 131: pii: jcs218024.

  11. Nguyen, Thi Tuyet Mai*, Y. Murakami*, E. Sheridan*, S. Ehresmann, J. Rousseau, A. St-Denis, G. Chai, N. F. Ajeawung, L. Fairbrother, T. Reimschisel, A. Bateman, E. Berry-Kravis, F. Xia, J. Tardif, D. A. Parry, C. V. Logan, C. Diggle, C. P. Bennett, L. Hattingh, J. A. Rosenfeld, M. S. Perry, M. J. Parker, F. Le Deist, M. S. Zaki, E. Ignatius, P. Isohanni, T. Loennqvist, C. J. Carroll, C. A. Johnson, J. G. Gleeson, T. Kinoshita and P. M. Campeau. (2017) Mutations in GPAA1, encoding a GPI transamidase complex protein, cause developmental delay, epilepsy, cerebellar atrophy, and osteopenia. Am. J. Hum. Genet., 101:856-865.

  12. Liu, Y.-S., X.-Y. Guo, T. Hirata, Y. Rong, D. Motooka, T. Kitajima, Y. Murakami, X.-D. Gao, S. Nakamura, T. Kinoshita and M. Fujita. (2017) N-Glycan dependent protein folding and endoplasmic reticulum retention regulate GPI-anchor processing. J. Cell Biol., 217: 585-599.

  13. Hirata, T., S. K. Mishra, S. Nakamura, K. Saito, D. Motooka, Y. Takada, N. Kanzawa, Y. Murakami, Y. Maeda, M. Fujita, Y. Yamaguchi and T. Kinoshita. (2017) Identification of a Golgi GPI-N-acetylgalactosamine transferase with tandem transmembrane regions in the catalytic domain. Nat. Commun., 9:405.

  14. Lee, G-H., Fujita, M., Takaoka, K., Murakami, Y., Fujihara, Y., Kanzawa, N., Murakami, K., Kajikawa, E.,  Takada, Y., Saito, K., Ikawa, M., Hamada, H., Maeda, Y., and Kinoshita, T. (2016) A GPI processing phospholipase A2, PGAP6, modulates Nodal signaling in embryos by shedding CRIPTO. J. Cell Biol. 215, 705-718
  15. Fujita, M., Watanabe, R., Jaensch, N., Romanova-Michaelides, M., Satoh, T., Kato, M., Riezman, H., Yamaguchi, Y., Maeda, Y., and Kinoshita, T. (2011) Sorting of GPI-anchored proteins into ER-exit sites by p24 proteins is dependent on remodeled GPI. J. Cell Biol. 194, 61-75
  16. Fujita, M., Maeda, Y., Ra, M., Yamaguchi, Y., Taguchi, R., and Kinoshita T. (2009) GPI-glycan remodeling by PGAP5 regulates transport of GPI-anchored proteins from the ER to the Golgi. Cell, 139, 352-365
  17. Maeda, Y., Ide, T., Koike, M., Uchiyama, Y., and Kinoshita, T. (2008) GPHR is a novel anion channel critical for acidification and functions of the Golgi apparatus. Nat. Cell Biol. 10, 1135–1145
  18. Maeda, Y., Tashima, Y., Houjou, T., Fujita, M., Yoko-o, T., Jigami, Y., Taguchi, R., and Kinoshita, T. (2007) Fatty acid remodeling of GPI-anchored proteins is required for their raft association. Mol. Biol. Cell, 18, 1497-1506 


  1. Kinoshita, T. (2018) Congenital defects in the expression of the glycosylphosphatidylinositol-anchored complement regulatory proteins CD59 and decay-accelerating factor. Semin. Hematol., 55:136-140.
  2. Ferguson, M. A. J., Hart, G. W. and Kinoshita, T.  (2017) Glycosylphosphatidylinositol anchors. In Essentials of Glycobiology 3rd ed. Varki, A., Cummings, R.D., Esko, J.D., Stanley, P., Hart, G.W., Aebi, M., Darvill, A., Kinoshita, T., Packer, N.J., Prestegard, J., Schnaar, R., Seeberger, P. (eds.), p137-150. Cold Spring Harbor Laboratory Press: Cold Spring Harbor, NY.

  3. Kinoshita, T., and Fujita, M. (2016) Biosynthesis of GPI-anchored proteins: special emphasis on GPI lipid remodeling. J. Lipid Res. 57, 6-24
  4. Hill, A., DeZern, A. E., Kinoshita, T., and Brodsky, R. A. (2017) Paroxysmal Nocturnal Haemoglobinuria. Nat. Rev. Dis. Prime. 3, 17028