Association of ezrin with intercellular adhesion molecule-1 and -2 (ICAM-1 and ICAM-2). Regulation by phosphatidylinositol 4, 5-bisphosphate.
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 calculated KD value was 3.3 x 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.
Heiska
L
L
Department of Pathology, University of Helsinki, Haartman Institute, 00014 Helsinki, Finland.
Alfthan
K
K
Grönholm
M
M
Vilja
P
P
Vaheri
A
A
Carpén
O
O
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D000943:Antigens, Differentiation; D019556:COS Cells; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D019084:Fluorescent Antibody Technique, Indirect; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D008954:Models, Biological; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D014162:Transfection; D000099149:Ezrin
D015703:Antigens, CD; D000943:Antigens, Differentiation; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D018799:Intercellular Adhesion Molecule-1; D019269:Phosphatidylinositol 4,5-Diphosphate; D010750:Phosphoproteins; D000099149:Ezrin; C065289:ICAM2 protein, human; C483616:ICAM3 protein, human