Journal of Plant Research

, Volume 130, Issue 3, pp 475–478 | Cite as

Novel insights into the molecular mechanism of sperm–egg fusion via IZUMO1

JPR Symposium Fusion in Fertilization: Interdisciplinary Collaboration among Plant and Animal Scientists

Abstract

When a spermatozoon fertilizes an oocyte in mammals, there must be an extremely precise regulation system for successful gamete fusion to occur, which is the final step of fertilization. Using gene-modified animals, IZUMO1 on the sperm side and its receptor, JUNO, on the ovum side, have been unveiled as indispensable factors for triggering membrane fusion. We recently analyzed the detailed molecular machinery of the IZUMO1–JUNO recognition system and clarified the tertiary architecture of the IZUMO1–JUNO complex based on the crystal structure. Over the past 2 years, important discoveries have successively emerged, presenting a new perspective on fertilization. In this mini-review, I will initially explain the historical background of the molecular mechanism study of gamete fusion, and go on to describe our latest study data.

Keywords

Fertilization Gamete fusion IZUMO1 JUNO 

References

  1. Almeida EA, Huovila AP, Sutherland AE, Stephens LE, Calarco PG, Shaw LM, Mercurio AM, Sonnenberg A, Primakoff P, Myles DG, White JM (1995) Mouse egg integrin alpha 6 beta 1 functions as a sperm receptor. Cell 81:1095–1104CrossRefPubMedGoogle Scholar
  2. Aydin H, Sultana A, Li S, Thavalingam A, Lee JE (2016) Molecular architecture of the human sperm IZUMO1 and egg JUNO fertilization complex. Nature 534:562–565CrossRefPubMedPubMedCentralGoogle Scholar
  3. Bianchi E, Doe B, Goulding D, Wright GJ (2014) Juno is the egg Izumo receptor and is essential for mammalian fertilization. Nature 508:483–487CrossRefPubMedPubMedCentralGoogle Scholar
  4. Blobel CP, Wolfsberg TG, Turck CW, Myles DG, Primakoff P, White JM (1992) A potential fusion peptide and an integrin ligand domain in a protein active in sperm-egg fusion. Nature 356:248–252CrossRefPubMedGoogle Scholar
  5. Cho C, Bunch DO, Faure JE, Goulding EH, Eddy EM, Primakoff P, Myles DG (1998) Fertilization defects in sperm from mice lacking fertilin beta. Science 281:1857–1859CrossRefPubMedGoogle Scholar
  6. Ellerman DA, Pei J, Gupta S, Snell WJ, Myles D, Primakoff P (2009) Izumo is part of a multiprotein family whose members form large complexes on mammalian sperm. Mol Reprod Dev 76:1188–1199CrossRefPubMedPubMedCentralGoogle Scholar
  7. Han L, Nishimura K, Sadat Al Hosseini H, Bianchi E, Wright GJ, Jovine L (2016) Divergent evolution of vitamin B9 binding underlies Juno-mediated adhesion of mammalian gametes. Curr Biol 26:R100–R101CrossRefPubMedPubMedCentralGoogle Scholar
  8. Ikawa M, Inoue N, Benham AM, Okabe M (2010) Fertilization: a sperm’s journey to and interaction with the oocyte. J Clin Invest 120:984–994CrossRefPubMedPubMedCentralGoogle Scholar
  9. Inoue N, Ikawa M, Isotani A, Okabe M (2005) The immunoglobulin superfamily protein Izumo is required for sperm to fuse with eggs. Nature 434:234–238CrossRefPubMedGoogle Scholar
  10. Inoue N, Ikawa M, Okabe M (2011) The mechanism of sperm-egg interaction and the involvement of IZUMO1 in fusion. Asian J Androl 13:81–87CrossRefPubMedGoogle Scholar
  11. Inoue N, Hamada D, Kamikubo H, Hirata K, Kataoka M, Yamamoto M, Ikawa M, Okabe M, Hagihara Y (2013) Molecular dissection of IZUMO1, a sperm protein essential for sperm-egg fusion. Development 140:3221–3229CrossRefPubMedGoogle Scholar
  12. Inoue N, Hagihara Y, Wright D, Suzuki T, Wada I (2015) Oocyte-triggered dimerization of sperm IZUMO1 promotes sperm-egg fusion in mice. Nat Commun 6:8858CrossRefPubMedPubMedCentralGoogle Scholar
  13. Kaji K, Oda S, Shikano T, Ohnuki T, Uematsu Y, Sakagami J, Tada N, Miyazaki S, Kudo A (2000) The gamete fusion process is defective in eggs of Cd9-deficient mice. Nat Genet 24:279–282CrossRefPubMedGoogle Scholar
  14. Kato K, Satouh Y, Nishimasu H, Kurabayashi A, Morita J, Fujihara Y, Oji A, Ishitani R, Ikawa M, Nureki O (2016) Structural and functional insights into IZUMO1 recognition by JUNO in mammalian fertilization. Nat Commun 7:12198CrossRefPubMedPubMedCentralGoogle Scholar
  15. Kim E, Yamashita M, Nakanishi T, Park KE, Kimura M, Kashiwabara S, Baba T (2006) Mouse sperm lacking ADAM1b/ADAM2 fertilin can fuse with the egg plasma membrane and effect fertilization. J Biol Chem 281:5634–5639CrossRefPubMedGoogle Scholar
  16. Klinovska K, Sebkova N, Dvorakova-Hortova K (2014) Sperm-egg fusion: a molecular enigma of mammalian reproduction. Int J Mol Sci 15:10652–10668CrossRefPubMedPubMedCentralGoogle Scholar
  17. Le Naour F, Rubinstein E, Jasmin C, Prenant M, Boucheix C (2000) Severely reduced female fertility in CD9-deficient mice. Science 287:319–321CrossRefPubMedGoogle Scholar
  18. Lorenzetti D, Poirier C, Zhao M, Overbeek PA, Harrison W, Bishop CE (2014) A transgenic insertion on mouse chromosome 17 inactivates a novel immunoglobulin superfamily gene potentially involved in sperm-egg fusion. Mamm Genome 25:141–148CrossRefPubMedGoogle Scholar
  19. Miyado K, Yamada G, Yamada S, Hasuwa H, Nakamura Y, Ryu F, Suzuki K, Kosai K, Inoue K, Ogura A, Okabe M, Mekada E (2000) Requirement of CD9 on the egg plasma membrane for fertilization. Science 287:321–324CrossRefPubMedGoogle Scholar
  20. Nishimura K, Han L, Bianchi E, Wright GJ, de Sanctis D, Jovine L (2016) The structure of sperm Izumo1 reveals unexpected similarities with Plasmodium invasion proteins. Curr Biol 26:R661–R662CrossRefPubMedPubMedCentralGoogle Scholar
  21. Ohto U, Ishida H, Krayukhina E, Uchiyama S, Inoue N, Shimizu T (2016) Structure of IZUMO1–JUNO reveals sperm–oocyte recognition during mammalian fertilization. Nature 534:566–569CrossRefPubMedGoogle Scholar
  22. Satouh Y, Inoue N, Ikawa M, Okabe M (2012) Visualization of the moment of mouse sperm-egg fusion and dynamic localization of IZUMO1. J Cell Sci 125:4985–4990CrossRefPubMedGoogle Scholar
  23. Snell WJ, White JM (1996) The molecules of mammalian fertilization. Cell 85:629–637CrossRefPubMedGoogle Scholar
  24. Zhu X, Bansal NP, Evans JP (2000) Identification of key functional amino acids of the mouse fertilin beta (ADAM2) disintegrin loop for cell–cell adhesion during fertilization. J Biol Chem 275:7677–7683CrossRefPubMedGoogle Scholar

Copyright information

© The Botanical Society of Japan and Springer Japan 2016

Authors and Affiliations

  1. 1.Department of Cell Science, School of Medicine, Institutes for Biomedical SciencesFukushima Medical UniversityFukushima-CityJapan

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