Association of intercellular adhesion molecule-1 (ICAM-1) with actin-containing cytoskeleton and alpha-actinin.

Abstract

We have studied the cytoskeletal association of intercellular adhesion molecule-1 (ICAM-1, CD54), an integral membrane protein that functions as a counterreceptor for leukocyte integrins (CD11/CD18). A linkage between ICAM-1 and cytoskeletal elements was suggested by studies showing a different ICAM-1 staining pattern for COS cells transfected with wild-type ICAM-1 or with an ICAM-1 construct that replaces the cytoplasmic and transmembrane domains of ICAM-1 with a glycophosphatidylinositol (GPI) anchor. Wild-type ICAM-1 appeared to localize most prominently in microvilli whereas GPI-ICAM-1 demonstrated a uniform cell surface distribution. Disruption of microfilaments with cytochalasin B (CCB) changed the localization of wild-type ICAM-1 but had no effect on GPI-ICAM-1. Some B-cell lines demonstrated a prominent accumulation of ICAM-1 into the uropod region whereas other cell surface proteins examined were not preferentially localized. CCB also induced redistribution of ICAM-1 in these cells. For characterization of cytoskeletal proteins interacting with ICAM-1, a 28-residue peptide that encompasses the entire predicted cytoplasmic domain (ICAM-1,478- 505) was synthesized, coupled to Sepharose-4B, and used as an affinity matrix. One of the most predominant proteins eluted either with soluble ICAM-1,478-505-peptide or EDTA, was 100 kD, had a pI of 5.5, and in Western blots reacted with alpha-actinin antibodies. A direct association between alpha-actinin and ICAM-1 was demonstrated by binding of purified alpha-actinin to ICAM-1,478-505-peptide and to immunoaffinity purified ICAM-1 and by a strict colocalization of ICAM-1 with alpha-actinin, but not with the cytoskeletal proteins talin, tensin, and vinculin. The region of ICAM-1,478-505 interacting with alpha-actinin was mapped to the area close to the membrane spanning region. This region contains several positively charged residues and appears to mediate a charged interaction with alpha-actinin which is not highly dependent on the order of the residues.

RKIKK Motif in the Intracellular Domain Is Critical for Spatial and Dynamic Organization of ICAM-1: Functional Implication for the Leukocyte Adhesion and Transmigration

“…Leukocyte TEM is inhibited after the inactivation of endothelial cells' Rho protein function (Adamson et al, 1999), thereby suggesting a proactive role for ICAM-1 signaling/cytoskeletal interactions in facilitating TEM. In agreement with these lines, the intracellular domain of ICAM-1 can bind to a variety of molecules, such as ␣-actinin (Carpen et al, 1992), ␤-tubulin, GAPDH (Federici et al, 1996), and ezrin (Heiska et al, 1998). These proteins all have the potential to perform signaling functions.…”

“…Earlier reports have demonstrated that native ICAM-1 protein is associated with the actin-containing microfilament network and that their interaction is mediated by the cytoplasmic or transmembrane domains of ICAM-1 (Carpen et al, 1992;Carman et al, 2003). ICAM-1 has also been known to be associated with ezrin/radixin/moesin (ERM) family members, i.e., ezrin and moesin (Heiska et al, 1998;Barreiro et al, 2002).…”

“…Because ICAM-1 also has been known to associate with ezrin and moesin (Carpen et al, 1992;Barreiro et al, 2002), we therefore tested whether the overexpression of ICAM-1 by itself directly induces microvillar elongation in COS-7 cells. As shown in Figure 3A, the elongation of microvilli as well as F-actin formation, were significantly increased in cells that express higher levels of ICAM-1, as determined by flow cytometry and confocal analysis.…”

Slit modulates cerebrovascular inflammation and mediates neuroprotection against global cerebral ischemia

“…The requisite first step involves the low-affinity "rolling" of the leukocyte on the endothelium through the engagement of selectins (E-, P-, and L-selectin) with their ligands, PSGL-1 and sialyl LewisX, followed by a high-affinity "firm" adhesion mediated by leukocyte integrins binding to the endothelial intercellular adhesion molecule (ICAM-1) (Alon et al, 2003). The cytoplasmic domains of the integrins, selectins, and ICAM-1 are linked to the cytoskeleton through adapter actin-binding proteins, allowing for direct associations between integrins and cytoskeletal function (Sampath et al, 1998;Yoshida et al, 1996;Carpen et al, 1992). The intracellular mechanisms by which Slit negatively regulated leukocyte-endothelial dynamics in the cerebral microcirculation was not investigated in the present study, but available evidence supports the following sequence of events: Slit interaction with the extracellular domain of its single transmembrane domain receptor Robo promotes an association of the Slit-Robo complex with a novel family of Rho GTPase-activating proteins (GAPs) forming Slit-Robo GAPs (srGAPs) (Wong et al, 2001).…”

Evidence from sequence information that the interleukin-1 receptor is a transmembrane GTPase

“…Furthermore, this group appears to be extremely ancient, as is evidenced by the recent discovery of Ig/tyrosine kinase receptors in animals as primitive as sponges (Schaecke et al, 1994). Many Ig superfamily receptors do not contain tyrosine kinase domains, however, and several have been found to possess cytoplasmic domains belonging to the family of protein tyrosine phosphatases (Krueger & Saito, 1992) or to possess short cytoplasmic tails that do not exhibit intrinsic activities but which are required for binding to other cytoplasmic functional proteins such as a-actinin (Carpen et al, 1992), actin (Letourneau & Shattuck, 1989), and spectrin (Pollenberg et al, 1987). Other Ig superfamily members, such as the memReprint requests to: Thomas P. Hopp brane forms of Igs themselves, possess cytoplasmic domains of only one or several amino acids and rely on other transmembrane proteins for signal transduction (Keegan & Paul, 1992).…”