Amphiphysin I and regulation of synaptic vesicle endocytosis

Yumei Wu, Hideki Matsui, Kazuhito Tomizawa

Research output: Contribution to journalReview article

26 Citations (Scopus)

Abstract

Amphiphysin I, known as a major dynamin-binding partner localized on the collars of nascent vesicles, plays a key role in clathrin-mediated endocytosis (CME) of synaptic vesicles. Amphiphysin I mediates the invagination and fission steps of synaptic vesicles by sensing or facilitating membrane curvature and stimulating the GTPase activity of dynamin. Amphiphysin I may form a homodimer by itself or a heterodimer with amphiphysin II in vivo. Both amphiphysin I and II function as multilinker proteins in the clathrin-coated complex. Under normal physiological conditions, the functions of amphiphysin I and some other endocytic proteins are known to be regulated by phosphorylation and dephosphorylation. During hyperexcited conditions, the most recent data showed that amphiphysin I is truncated by the ca2 -dependent protease calpain. Overexpression of the truncated form of amphiphysin I inhibited transferrin uptake and synaptic vesicle endocytosis (SVE). This suggests that amphiphysin I may be an important regulator for SVE when massive amounts of Ca2+ flow into presynaptic terminals, a phenomenon observed in neurodegenerative disorders such as ischemia/anoxia, epilepsy, stroke, trauma and Alzheimer's disease. This review describes current knowledge regarding the general properties and functions of amphiphysin I as well as the functional regulations such as phosphorylation and proteolysis in nerve terminals.

Original languageEnglish
Pages (from-to)305-323
Number of pages19
JournalActa medica Okayama
Volume63
Issue number6
Publication statusPublished - Dec 2009

Keywords

  • Amphiphysin I
  • Calpain
  • Hyperexcitation
  • SVE
  • Seizure

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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  • Cite this

    Wu, Y., Matsui, H., & Tomizawa, K. (2009). Amphiphysin I and regulation of synaptic vesicle endocytosis. Acta medica Okayama, 63(6), 305-323.