P-Selectin Glycoprotein Ligand-1 Forms Dimeric Interactions with E-Selectin but Monomeric Interactions with L-Selectin on Cell Surfaces

• Authors: Yan Zhang, Georgia Institute of Technology; Ning Jiang, Georgia Institute of Technology; Veronika Zarnitsyna, Emory University; Arkadiusz G. Klopocki, University of Oklahoma; Rodger P. McEver, University of Oklahoma; Cheng Zhu, Emory University
• Journal Title: PLOS ONE
• Volume: Volume 8, Number 2
• Publisher: PUBLIC LIBRARY SCIENCE | 2013-02-25, Pages e57202-e57202
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1371/journal.pone.0057202
• Subjects: Biology, Cell
• Keywords: Science & Technology; Multidisciplinary Sciences; Science & Technology - Other Topics; CLATHRIN-COATED PITS; LEUKOCYTE ADHESION; 2-DIMENSIONAL KINETICS; BINDING-KINETICS; RECEPTOR; INTEGRIN; TRANSMEMBRANE; DIMERIZATION; BONDS; IDENTIFICATION

Abstract

Interactions of selectins with cell surface glycoconjugates mediate the first step of the adhesion and signaling cascade that recruits circulating leukocytes to sites of infection or injury. P-selectin dimerizes on the surface of endothelial cells and forms dimeric bonds with P-selectin glycoprotein ligand-1 (PSGL-1), a homodimeric sialomucin on leukocytes. It is not known whether leukocyte L-selectin or endothelial cell E-selectin are monomeric or oligomeric. Here we used the micropipette technique to analyze two-dimensional binding of monomeric or dimeric L- and E-selectin with monomeric or dimeric PSGL-1. Adhesion frequency analysis demonstrated that E-selectin on human aortic endothelial cells supported dimeric interactions with dimeric PSGL-1 and monomeric interactions with monomeric PSGL-1. In contrast, L-selectin on human neutrophils supported monomeric interactions with dimeric or monomeric PSGL-1. Our work provides a new method to analyze oligomeric cross-junctional molecular binding at the interface of two interacting cells.