Role of Cholesterol in Formation and Function of a Signaling Complex Involving αvβ3, Integrin-Associated Protein (Cd47), and Heterotrimeric G Proteins

Green, Jennifer M.; Zheleznyak, Alexander; Chung, Jun; Lindberg, Frederik P.; Sarfati, Marika; Frazier, William A.; Brown, Eric J.

doi:10.1083/jcb.146.3.673

Cited by 166 publications

(166 citation statements)

References 54 publications

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“…Interestingly, the α v β 3 integrin expressed by human ovarian carcinoma cells (OV10) is linked to G proteins by an adaptor molecule known as integrin associated protein or CD47 (Green et al, 1999). Cholesterol depletion by methyl-β-cyclodextrin disrupts the linkage between the integrin and G proteins in these cells, an effect that was reversed by repletion of methyl-β-cyclodextrin extracted cholesterol (Green et al, 1999). This observation is particularly interesting for two reasons.…”

Section: Discussionmentioning

confidence: 91%

“…Plasma membrane microdomains, typically defined by their resistance to detergent solubilization, are enriched with cholesterol and glycosphingolipids which are known to interact directly with integrins (Pande, 2000). Interestingly, the α v β 3 integrin expressed by human ovarian carcinoma cells (OV10) is linked to G proteins by an adaptor molecule known as integrin associated protein or CD47 (Green et al, 1999). Cholesterol depletion by methyl-β-cyclodextrin disrupts the linkage between the integrin and G proteins in these cells, an effect that was reversed by repletion of methyl-β-cyclodextrin extracted cholesterol (Green et al, 1999).…”

Section: Discussionmentioning

confidence: 99%

“…Integrin supramolecular complexes (SMCs) were isolated from homogenates of cultured rat trigeminal ganglion neurons and associated molecules were identified by Western blot using monospecific antibodies (Green et al, 1999). Figure 4, lane 1 demonstrates MOR and G αi in RGD-binding integrin SMCs isolated in 100 mM NaCl-containing buffer.…”

Section: Mor Is Isolated In Rgd-binding Integrin Supramolecular Complmentioning

confidence: 99%

“…Integrin supramolecular complexes were extracted from rat trigeminal ganglion neuron cultures in T-25 flasks after 5 days in culture using a method adopted from Green et al (Green et al, 1999). RGD or DGR peptides were coupled to 4.5 micron carboxyl-activated ferromagnetic beads (Spherotech, Libertyville, IL) as described by the manufacturer.…”

Section: Isolation Of Integrin Supramolecular Complexesmentioning

confidence: 99%

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Integrins regulate opioid receptor signaling in trigeminal ganglion neurons

Berg

Zardeneta²,

Hargreaves

et al. 2007

Neuroscience

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The binding of integrins to the extracellular matrix results in focal organization of the cytoskeleton and the genesis of intracellular signals that regulate vital neuronal functions. Recent evidence suggests that integrins modulate G-protein coupled receptor (GPCR) signaling in hippocampal neurons. In this study we evaluated the hypothesis that integrins regulate the mu opioid receptor in rat trigeminal ganglion neurons. For these studies, primary cultures of adult rat trigeminal ganglion neurons were used to demonstrate the colocalization of β1 and β3 integrins with mu opioid receptor in caveolin-1-rich membrane fractions, and at focal adhesions sites generated by integrin ligand binding. Furthermore, we show that the mu opioid receptor agonist, DAMGO ([DAla 2 ,N-MePhe 4 ,Gly-ol 5 ]enkephalin), inhibits cAMP accumulation in response to PGE 2 stimulation in bradykinin-primed, but not unprimed, cultured trigeminal ganglia neurons. Application of soluble GRGDS (Gly-Arg-Gly-Asp-Ser) peptides that bind specific integrins (i.e., RGD-binding integrins) completely abolished the DAMGO effect in bradykinin-primed trigeminal ganglia neurons, but did not alter bradykinin-mediated hydrolysis of phosphytidylinositol. Likewise, monospecific anti-β1 and anti-β3 integrin subunit antibodies blocked this DAMGO effect in bradykinin -primed trigeminal ganglia neurons. Indeed, application of anti-β1 integrin subunit actually reversed DAMGO signaling, resulting in increased cAMP accumulation in these cells. This suggests that the relative amounts of specific activated integrins at focal adhesions may govern signaling by the mu opioid receptor, perhaps by altering interactions with G proteins (e.g., Gαi vs. Gαs). Collectively, these data provide the first evidence that specific integrins regulate opioid receptor signaling in sensory neurons. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Cells interact with the extracellular matrix via heterodimeric (αβ) transmembrane receptors, termed integrins (Giancotti and Rouslahti, 1999). Integrins are expressed by virtually every cell type and are known to be involved in the regulation of several vital cell functions, including adhesion, migration, proliferation, and differentiation (Milam et al., 1991, Hynes, 1992, Curley et al., 1999, Giancotti and Rouslahti, 1999, Schlaepfer et al., 1999, Coppolino and Dedhar, 2000, Bouvard et al., 2001, Zamir and Geiger, 2001, Alenghat and Ingber, 2002, Martin et al., 2002, Miranti and Brugge, 2002. Eighteen α and eight β subunits have been identified forming at least 24 different αβ integrins (van der Fli...

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Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Mor Is Isolated In Rgd-binding Integrin Supramolecular Complmentioning

confidence: 99%

Section: Isolation Of Integrin Supramolecular Complexesmentioning

confidence: 99%

See 2 more Smart Citations

Integrins regulate opioid receptor signaling in trigeminal ganglion neurons

Berg

Zardeneta²,

Hargreaves

et al. 2007

Neuroscience

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“…As previously demonstrated for ␤ 3 integrins and ␣ 2 ␤ 1 , CD47 is physically associated with ␣ 4 ␤ 1 in cells, where it regulates function of this ␤ 1 integrin. Both CD47 (40,41) and ␣ 4 ␤ 1 integrin (42) associate with lipid rafts in Jurkat cells, suggesting that their interaction may involve these membrane microdomains. Notably, ␣ v ␤ 3 activity is increased when CD47 translocates out of raft domains (43).…”

Section: A Cd47-binding Peptide Stimulatesmentioning

confidence: 99%

Regulation of Integrin Function by CD47 Ligands

Barazi

Cashel

et al. 2002

Journal of Biological Chemistry

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CD47 (integrin-associated protein) is an integral membrane protein that is required for granulocyte and T cell recruitment to sites of infection (1, 2), and its absence on red blood cells leads to their rapid macrophage-mediated clearance (3). CD47 may also function as a costimulator to regulate T cell activation, survival, and Th1 versus Th2 differentiation (4, 5). Endogenous ligands for the extracellular domain of CD47 include the secreted protein thrombospondin-1 (TSP1) 1 and potentially other members of the thrombospondin family, several integrins (6 -9), and some members of the signal-regulatory protein family (3, 10 -13). Engagement of CD47 by soluble ligands or signal-regulatory protein counter receptors modulates several cell signaling pathways, including activation of a heterotrimeric G protein (14).Although some signal transduction through CD47 is integrin-independent (4, 15, 16), association of CD47 with certain integrins was found to modulate their function to mediate cell adhesion or motility (6,8,9,17). In addition to its known functional and physical interactions with ␣ v ␤ 3 , ␣ IIb ␤ 3 , and ␣ 2 ␤ 1 integrins, several publications have suggested an association of CD47 with ␣ 4 ␤ 1 integrin. CD47 and ␣ 4 ␤ 1 were colocalized on microvilli of K562 erythroleukemia cells (18), and CD47-dependent arrest of T cells on inflammatory endothelium could be blocked by antibodies that prevent ␣ 4 ␤ 1 integrin binding to VCAM-1 (2). In the latter study, ligation of CD47 by TSP1 or signal-regulatory protein 1␣ was inferred to activate ␣ 4 ␤ 1 integrin on T cells, although this was not demonstrated either functionally or biochemically.We recently found that CD47 expression is required for stimulation of T cell motility and expression of MMP-2 stimulated by ␣ 4 ␤ 1 integrin ligands (19). An antibody to CD47 also blocked the motility response to an ␣ 4 ␤ 1 integrin ligand (19). Therefore, at least a functional interaction occurs between CD47 and ␣ 4 ␤ 1 integrin.We identified a binding site for ␣ 4 ␤ 1 integrin in the Nterminal domains of TSP1 and TSP2 (19), whereas two binding sites for CD47 have been localized to the C-terminal domain of TSP1 (for review, see Ref. 20). Thus, TSP1 could potentially regulate its own interaction with ␣ 4 ␤ 1 integrin through simultaneous interactions with CD47 and ␣ 4 ␤ 1 integrin on a T cell, analogous to the ability of soluble TSP1 to stimulate ␣ v ␤ 3 integrin-dependent melanoma cell adhesion to immobilized TSP1 (21).To define a molecular basis for functional cross-talk between these two receptors, we have examined the effect of CD47 ligands on the function of ␣ 4 ␤ 1 integrin in T cells and melanoma cells. We confirmed that ligation of CD47 can activate ␣ 4 ␤ 1 integrin function but unexpectedly found the mechanism of this activity to be CD47 ligand-dependent. We further show that CD47 ligation differentially activates and inactivates ␣ v ␤ 3 and ␣ 4 ␤ 1 in melanoma cells and ␣ 4 ␤ 1 and ␣ 5 ␤ 1 in Jurkat cells. Unexpectedly, but consistent with a recent report demonstrating C...

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Modulation of ?5?1 integrin functions by the phospholipid and cholesterol contents of cell membranes

Gopalakrishna¹,

Chaubey²,

Manogaran³

et al. 2000

J. Cell. Biochem.

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Several modifications of the alpha5beta1 integrin, which alter its intracellular and extracellular interaction with fibronectin and other proteins, have been reported. However, the significance of the lateral mobility of integrin molecules in the plasma membrane, as a regulator of their distribution and function, is poorly understood. We examined this problem by increasing the cholesterol content of plasma membranes, and consequently modifying the fluidity of membrane phospholipids, in rat fibroblasts. Under these conditions, the clustering of alpha5beta1 integrin molecules in focal adhesions, their adhesion to the cell-binding domain of fibronectin, and their association with the cytoskeletal protein talin were significantly enhanced as compared to control cells. However, the activation of MAP-kinase pathways by the association of fibronectin with alpha5beta1 integrin, and its association with integrin-linked kinase (ilk), were suppressed. The treated cells also showed distinct changes in shape, and their actin stress fiber network was more dense and thick as compared to control cells. The changes in fluidity of phospholipids occurred differentially and fluidity of phosphatidyl-ethanolamine increased, while that of phosphatidyl-choline was reduced. Our results suggest that proteins in focal adhesions could be partitioned in specific lipid domains, which regulate specific aspects of alpha5beta1 integrin functions.

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Role of Cholesterol in Formation and Function of a Signaling Complex Involving αvβ3, Integrin-Associated Protein (Cd47), and Heterotrimeric G Proteins

Cited by 166 publications

References 54 publications

Integrins regulate opioid receptor signaling in trigeminal ganglion neurons

Integrins regulate opioid receptor signaling in trigeminal ganglion neurons

Regulation of Integrin Function by CD47 Ligands

Modulation of ?5?1 integrin functions by the phospholipid and cholesterol contents of cell membranes

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