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© The Rockefeller University Press,
0021-9525/2000//243 $5.00
The Journal of Cell Biology, Volume 150, Number 1,
, 2000 243-252
Original Article |
Intercellular Adhesion Molecule-5 Induces Dendritic Outgrowth by Homophilic Adhesion
carl.gahmberg{at}helsinki.fi
Intercellular adhesion molecule-5 (ICAM-5) is a dendritically polarized membrane glycoprotein in telencephalic neurons, which shows heterophilic binding to leukocyte β2-integrins. Here, we show that the human ICAM-5 protein interacts in a homophilic manner through the binding of the immunoglobulin domain 1 to domains 4–5. Surface coated ICAM-5-Fc promoted dendritic outgrowth and arborization of ICAM- 5–expressing hippocampal neurons. During dendritogenesis in developing rat brain, ICAM-5 was in monomer form, whereas in mature neurons it migrated as a high molecular weight complex. The findings indicate that its homophilic binding activity was regulated by nonmonomer/monomer transition. Thus, ICAM-5 displays two types of adhesion activity, homophilic binding between neurons and heterophilic binding between neurons and leukocytes.
Key Words: leukocyte integrin adhesion dendrite neuron
© 2000 The Rockefeller University Press
Abbreviations used in this paper: AxCAM, axon-associated cell adhesion molecule; D, immunoglobulin domain; DenCAM, dendrite-associated cell adhesion molecule; E19, embryonic day 19; ICAM, intercellular adhesion molecule; MAP-2, microtubule-associated protein-2; P, postnatal day; WT, wild-type.
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