Association of Ezrin with Intercellular Adhesion Molecule-1 and -2 (ICAM-1 and ICAM-2)

doi:10.1074/jbc.273.34.21893

Association of Ezrin with Intercellular Adhesion Molecule-1 and -2 (ICAM-1 and ICAM-2)

REGULATION BY PHOSPHATIDYLINOSITOL 4,5-BISPHOSPHATE*

From the Departments of ^‡Pathology and ^‖Virology, University of Helsinki, Haartman Institute, 00014 Helsinki, ^§VTT Biotechnology and Food Research, FIN-02044 VTT (Espoo), and ^¶Medical School, University of Tampere, 33101 Tampere, Finland

Abstract

Ezrin is a cytoplasmic linker molecule between plasma membrane components and the actin-containing cytoskeleton. We studied whether ezrin is associated with intercellular adhesion molecule (ICAM)-1, -2, and -3. In transfected cells, ICAM-1 and ICAM-2 colocalized with ezrin in microvillar projections, whereas an ICAM-1 construct attached to cell membrane via a glycophosphatidylinositol anchor was uniformly distributed on the cell surface. An interaction of ICAM-2 and ezrin was seen by affinity precipitation, microtiter binding assay, coimmunoprecipitation, and surface plasmon resonance methods. The calculatedK _D value was 3.3 × 10⁻⁷ m. Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P₂) induced an interaction of ezrin and ICAM-1 and enhanced the interaction of ezrin and ICAM-2, but ICAM-3 did not bind ezrin even in the presence of PtdIns(4,5)P₂. PtdIns(4,5)P₂ was shown to bind to cytoplasmic tails of ICAM-1 and ICAM-2, which are the first adhesion proteins demonstrated to interact with PtdIns(4,5)P₂. The results indicate an interaction of ezrin with ICAM-1 and ICAM-2 and suggest a regulatory role of phosphoinositide signaling pathways in regulation of ICAM-ezrin interaction.

Footnotes

↵* This work was supported by the Academy of Finland, the Finnish Cancer Society, the Sigrid Juselius Foundation, and the Ida Montin Foundation.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵** To whom correspondence should be addressed: Haartman Institute, University of Helsinki, P. O. Box 21 (Haartmanink. 3), FIN-00014 Helsinki, Finland. Tel.: 358-9-19126413; Fax: 358-9-19126700; E-mail:olli.carpen{at}helsinki.fi.
Abbreviations:

ERM

ezrin/radixin/moesin

GPI

glycophosphatidylinositol

HA

hemagglutinin antigen

ICAM

intercellular adhesion molecule

PC

phosphatidylcholine

PS

phosphatidylserine

PtdIns(4

5)P₂, phosphatidylinositol 4,5-bisphosphate

SPR

surface plasmon resonance

mAb

monoclonal antibody

PAGE

polyacrylamide gel electrophoresis

RU

resonance unit(s)

PBS

phosphate-buffered saline.
- Received January 16, 1998.
- Revision received May 14, 1998.
The American Society for Biochemistry and Molecular Biology, Inc.