pH-dependent Binding of the Epsin ENTH Domain and the AP180 ANTH Domain to PI(4,5)P2-containing Bilayers

Robert A. Hom, Mohsin Vora, Maryann Regner, Oksana M. Subach, Wonhwa Cho, Vladislav V. Verkhusha, Robert V. Stahelin, Tatiana G. Kutateladze

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31 Scopus citations

Abstract

Epsin and AP180 are essential components of the endocytotic machinery, which controls internalization of protein receptors and other macromolecules at the cell surface. Epsin and AP180 are recruited to the plasma membrane by their structurally and functionally related N-terminal ENTH and ANTH domains that specifically recognize PtdIns(4,5)P2. Here, we show that membrane anchoring of the ENTH and ANTH domains is regulated by the acidic environment. Lowering the pH enhances PtdIns(4,5)P2 affinity of the ENTH and ANTH domains reinforcing their association with lipid vesicles and monolayers. The pH dependency is due to the conserved histidine residues of the ENTH and ANTH domains, protonation of which is necessary for the strong PtdIns(4,5)P2 recognition, as revealed by liposome binding, surface plasmon resonance, NMR, monolayer surface tension and mutagenesis experiments. The pH sensitivity of the ENTH and ANTH domains is reminiscent to the pH dependency of the FYVE domain suggesting a common regulatory mechanism of membrane anchoring by a subset of the PI-binding domains.

Original languageEnglish (US)
Pages (from-to)412-423
Number of pages12
JournalJournal of molecular biology
Volume373
Issue number2
DOIs
StatePublished - Oct 19 2007

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Keywords

  • ANTH
  • ENTH
  • epsin
  • membrane
  • PtdIns(4,5)P

ASJC Scopus subject areas

  • Virology

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