α-Actinin-dependent cytoskeletal anchorage is important for ICAM-5-mediated neuritic outgrowth

University of Helsinki, Helsinki, Uusimaa, Finland
Journal of Cell Science (Impact Factor: 5.43). 09/2006; 119(Pt 15):3057-66. DOI: 10.1242/jcs.03045
Source: PubMed


Intercellular adhesion molecule-5 (ICAM-5, telencephalin) is a dendrite-expressed membrane glycoprotein of telencephalic neurons in the mammalian brain. By deletion of the cytoplasmic and membrane-spanning domains of ICAM-5, we observed that the membrane distribution of ICAM-5 was determined by the cytoplasmic portion. Therefore we have characterized the intracellular associations of ICAM-5 by using a bacterially expressed glutathione S-transferase (GST) fusion protein encompassing the cytoplasmic part of ICAM-5. One of the main proteins in the neuronal cell line Paju that bound to the ICAM-5 cytodomain was alpha-actinin. ICAM-5 expressed in transfected Paju cells was found in alpha-actinin immunoprecipitates, and ICAM-5 colocalized with alpha-actinin both in Paju cells and in dendritic filopodia and spines of primary hippocampal neurons. We were also able to coprecipitate alpha-actinin from rat brain homogenate. Binding to alpha-actinin appeared to be mediated mainly through the N-terminal region of the ICAM-5 cytodomain, as the ICAM-5(857-861) cytoplasmic peptide (KKGEY) mediated efficient binding to alpha-actinin. Surface plasmon resonance analysis showed that the turnover of the interaction was rapid. In a mutant cell line, Paju-ICAM-5-KK/AA, the distribution was altered, which implies the importance of the lysines in the interaction. Furthermore, we found that the ICAM-5/alpha-actinin interaction is involved in neuritic outgrowth and the ICAM-5(857-861) cytoplasmic peptide induced morphological changes in Paju-ICAM-5 cells. In summary, these results show that the interaction between ICAM-5 and alpha-actinin is mediated through binding of positively charged amino acids near the transmembrane domain of ICAM-5, and this interaction may play an important role in neuronal differentiation.

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Available from: Li Tian, Oct 06, 2015
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    • "All PCR-derived clones were verified by sequencing. The GST-a-actinin and the GST- ICAM-5cyto fusion proteins representing the ICAM-5 cytoplasmic domain were purified by affinity chromatography as described previously (Gilmore et al., 1994; Nyman-Huttunen et al., 2006). "
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    ABSTRACT: ICAM-5 is a negative regulator of dendritic spine maturation and facilitates the formation of filopodia. Its absence results in improved memory functions, but the mechanisms have remained poorly understood. Activation of NMDA receptors induces ICAM-5 ectodomain cleavage through a matrix metalloproteinase (MMP)-dependent pathway, which promotes spine maturation and synapse formation. Here, we report a novel, ICAM-5-dependent mechanism underlying spine maturation by regulating the dynamics and synaptic distribution of α-actinin. We found that GluN1 and ICAM-5 partially compete for the binding to α-actinin; deletion of the cytoplasmic tail of ICAM-5 or ablation of the gene resulted in increased association of GluN1 with α-actinin, whereas internalization of ICAM-5 peptide perturbed the GluN1/α-actinin interaction. NMDA treatment decreased α-actinin binding to ICAM-5, and increased the binding to GluN1. Proper synaptic distribution of α-actinin requires the ICAM-5 cytoplasmic domain, without which α-actinin tended to accumulate in filopodia, leading to F-actin reorganization. The results indicate that ICAM-5 retards spine maturation by preventing reorganization of the actin cytoskeleton, but NMDA receptor activation is sufficient to relieve the brake and promote the maturation of spines. © 2015. Published by The Company of Biologists Ltd.
    Biology Open 01/2015; 4(2). DOI:10.1242/bio.201410439 · 2.42 Impact Factor
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    • "The binding to -actinin [54] and ezrin [55] involves the sequence KKGEY in the membrane proximal part of the ICAM-5 cytoplasmic domain. When the cytoplasmic region was deleted or when the protein was anchored to the membrane through a glycophosphatidyl inositol-anchor, the distribution changed to a diffuse pattern in the plane of the membrane , whereas the full-length ICAM-5 molecule showed a more patchy distribution [54]. ICAM-5 co-localized with -actinin to the soma and dendritic shafts, and when this interaction was interrupted using a membrane-permeable KKGEY-containing peptide, it resulted in morphological changes of the cells and reduction in dendritic outgrowth. "
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    ABSTRACT: Cell adhesion is of utmost importance for normal development and cellular functions. ICAM-5 (intercellular adhesion molecule-5, telencephalin) is a member of the ICAM-family of adhesion proteins. These proteins bind to leukocyte beta(2)-integrins (CD11/CD18), but ICAM-5 is exceptional in several ways. It is solely expressed in the mammalian forebrain, appears at the time of birth, and is located in the soma and dendrites of neurons. It is structurally more complex than the others, and also shows homophilic adhesion. Recent studies show that it is important for the regulation of immunological activity in the brain and for the development of neuronal synapses and signal transmission.
    Immunology Letters 06/2008; 117(2):131-5. DOI:10.1016/j.imlet.2008.02.004 · 2.51 Impact Factor
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    • "Combining these data with the earlier fi ndings on ICAM-5 (Tian et al., 2000; Matsuno et al., 2006; Nyman-Huttunen et al., 2006), we present a schematic model depicting the NR-mediated spine development in which ICAM-5 is involved (Fig. 10). NMDA or AMPA stimulation causes increased MMP-2 and -9 activities in neurons and neighboring glial cells (not depicted), resulting in cleavage of the ectodomains of ICAM-5 from immature nascent spines. "
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    ABSTRACT: Matrix metalloproteinase (MMP)-2 and -9 are pivotal in remodeling many tissues. However, their functions and candidate substrates for brain development are poorly characterized. Intercellular adhesion molecule-5 (ICAM-5; Telencephalin) is a neuronal adhesion molecule that regulates dendritic elongation and spine maturation. We find that ICAM-5 is cleaved from hippocampal neurons when the cells are treated with N-methyl-d-aspartic acid (NMDA) or alpha-amino-3-hydroxy-5-methylisoxazole-propionic acid (AMPA). The cleavage is blocked by MMP-2 and -9 inhibitors and small interfering RNAs. Newborn MMP-2- and MMP-9-deficient mice brains contain more full-length ICAM-5 than wild-type mice. NMDA receptor activation disrupts the actin cytoskeletal association of ICAM-5, which promotes its cleavage. ICAM-5 is mainly located in dendritic filopodia and immature thin spines. MMP inhibitors block the NMDA-induced cleavage of ICAM-5 more efficiently in dendritic shafts than in thin spines. ICAM-5 deficiency causes retraction of thin spine heads in response to NMDA stimulation. Soluble ICAM-5 promotes elongation of dendritic filopodia from wild-type neurons, but not from ICAM-5-deficient neurons. Thus, MMPs are important for ICAM-5-mediated dendritic spine development.
    The Journal of Cell Biology 09/2007; 178(4):687-700. DOI:10.1083/jcb.200612097 · 9.83 Impact Factor
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