Rapid Ca2+-dependent decrease of protein ubiquitination at synapses

Hong Chen, Simona Polo, Pier Paolo Di Fiore, Pietro V. De Camilli

Research output: Contribution to journalArticle


Protein ubiquitination has been implicated in the regulation of axonal growth and synaptic plasticity as well as in the pathogenesis of neurodegenerative diseases. Here we show that depolarization-dependent Ca 2+ influx into synaptosomes produces a global, rapid (range of seconds), and reversible decrease of the ubiquitinated state of proteins, which correlates with the Ca2+-dependent dephosphorylation of several synaptic proteins. A similar general decrease in protein ubiquitination was observed in nonneuronal cells on Ca2+ entry induced by ionomycin. Both in synaptosomes and in nonneuronal cells, this decrease was blocked by FK506 (a calcineurin antagonist). Proteins whose ubiquitinated state was decreased include epsin 1, a substrate for the deubiquitinating enzyme fat facets/FAM, which we show here to be concentrated at synapses. These results reveal a fast regulated turnover of protein ubiquitination. In nerve terminals, protein ubiquitination may play a role both in the regulation of synaptic function, including vesicle traffic, and in the coordination of protein turnover with synaptic use.

Original languageEnglish
Pages (from-to)14908-14913
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number25
Publication statusPublished - Dec 9 2003

ASJC Scopus subject areas

  • Genetics
  • General

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