Epidermal growth factor receptor tyrosine kinase is modulated by GM3 interaction with N-linked GlcNAc termini of the receptor

100

102

Mounting evidence supports the notion that gangliosides serve regulatory roles in neurogenesis; little is known, however, about how these glycosphingolipids function in neural stem cell (NSC) fate determination. We previously demonstrated that ganglioside GD3 is a major species in embryonic mouse brain: more than 80% of the NSCs obtained by the neurosphere method express GD3. To investigate the functional role of GD3 in neurogenesis, we compared the properties of NSCs from GD3-synthase knockout (GD3S-KO) mice with those from their wild-type littermates. NSCs from GD3S-KO mice showed decreased self-renewal ability compared with those from the wild-type animals, and that decreased ability was accompanied by reduced expression of EGF receptor (EGFR) and an increased degradation rate of EGFR and EGF-induced ERK signaling. We also showed that EGFR switched from the low-density lipid raft fractions in wild-type NSCs to the high-density layers in the GD3S-KO NSCs. Immunochemical staining revealed colocalization of EGFR and GD3, and EGFR could be immunoprecipitated from the NSC lysate with an anti-GD3 antibody from the wild-type, but not from the GD3S-KO, mice. Tracking the localization of endocytosed EGFR with endocytosis pathway markers indicated that more EGFR in GD3S-KO NSCs translocated through the endosomal−lysosomal degradative pathway, rather than through the recycling pathway. Those findings support the idea that GD3 interacts with EGFR in the NSCs and that the interaction is responsible for sustaining the expression of EGFR and its downstream signaling to maintain the selfrenewal capability of NSCs.G angliosides are ubiquitously expressed in all vertebrate cells and are particularly abundant in the nervous system (1). In early mammalian embryonic brain, the pattern of ganglioside expression is limited to simple gangliosides, predominantly GM3 (NeuAcα2-3Galβ1-4Glcβ1-1′Cer) and GD3 (NeuAcα2-8NeuAcα2-3Galβ1-4Glcβ1-1′Cer). In later developmental stages, however, more complex gangliosides prevail, particularly GM1 (Galβ1-3GalNAcβ1-4(NeuAcα2-3)Galβ1-4Glcβ1-1′Cer), GD1a (NeuAcα2-3Galβ1-3GalNAcβ1-4(NeuAcα2-3)Galβ1-4Glcβ1-1′ Cer), GD1b (Galβ1-3GalNAcβ1-4(NeuAcα2-8NeuAcα2-3) Galβ1-4Glcβ1-1′Cer), and GT1b (NeuAcα2-3Galβ1-3GalNAcβ1-4 (NeuAcα2-8NeuAcα2-3)Galβ1-4Glcβ1-1′Cer) (2, 3). Because of the spatiotemporal expression patterns, gangliosides abundant in embryonic brain, such as GD3 and the c-series ganglioside antigen marker A2B5, have been considered to be useful stage-specific markers of early brain development (4, 5). Mounting evidence supports the notion that gangliosides serve regulatory roles in neurogenesis through modulating processes, such as intercellular recognition, interaction, adhesion, reception, and/ or signaling (6-9). Little is known, however, about how glycosphingolipids (GSLs) function in neural stem cell (NSC) fate determination. Investigation of the biological significance of gangliosides has also been greatly facilitated by the analysis of genetically engineered mice deficient in one or more gangl...

Section: Discussionmentioning

confidence: 58%

Section: Gd3 Interacts With Egfr and Plays A Role In Association Of Ementioning

confidence: 99%

Interaction of ganglioside GD3 with an EGF receptor sustains the self-renewal ability of mouse neural stem cells in vitro

Wang

2013

100

102

“…This possibility was tested by binding of CD82 to polystyrene beads coated with GSLs, using the procedure described in ref. 11. CD82 bound more strongly to beads coated with GM2-GM3 mixture than to beads coated with GM2 or GM3 alone or GM2-LacCer mixture (Fig.…”

Section: Specific Inhibitory Effect Of Gangliosides Gm2 and Gm3 On Momentioning

confidence: 99%

Ganglioside GM2/GM3 complex affixed on silica nanospheres strongly inhibits cell motility through CD82/cMet-mediated pathway

Todeschini

Santos

Handa

et al. 2008

Self Cite

115

Ganglioside GM2 complexed with tetraspanin CD82 in glycosynaptic microdomain of HCV29 and other epithelial cells inhibits hepatocyte growth factor-induced cMet tyrosine kinase. In addition, adhesion of HCV29 cells to extracellular matrix proteins also activates cMet kinase through ''cross-talk '' of integrins with cMet, leading to inhibition of cell motility and growth. Present studies indicate that cell motility and growth are greatly influenced by expression of GM2, GM3, or GM2/GM3 complexes, which affect cMet kinase activity of various types of cells, based on the following series of observations: (i) Cells expressing CD82, cultured with GM2 and GM3 cocoated on silica nanospheres, displayed stronger and more consistent motility inhibition than those cultured with GM2 or GM3 alone or with other glycosphingolipids. (ii) GM2-GM3, in the presence of Ca 2؉ form a heterodimer, as evidenced by electrospray ionization (ESI) mass spectrometry and by specific reactivity with mAb 8E11, directed to GM2/GM3 dimer structure. (iii) Cells expressing cMet and CD82 were characterized by enhanced motility associated with HGF-induced cMet activation. Both cMet and motility were strongly inhibited by culturing cells with GM2/GM3 dimer coated on nanospheres. (iv) Adhesion of HCV29 or YTS-1/CD82 cells to laminin-5-coated plate activated cMet kinase in the absence of HGF, whereas GM2/GM3 dimer inhibited adhesioninduced cMet kinase activity and inhibited cell motility. (v) Inhibited cell motility as in i, iii, and iv was restored to normal level by addition of mAb 8E11, which blocks interaction of GM2/GM3 dimer with CD82. Signaling through Src and MAP kinases is activated or inhibited in close association with cMet kinase, in response to GM2/GM3 dimer interaction with CD82. Thus, a previously uncharacterized GM2/GM3 heterodimer complexed with CD82 inhibits cell motility through CD82-cMet or integrin-cMet pathway.glycosphingolipid ͉ growth factor receptor ͉ ldlD cells ͉ tyrosine kinase G lycosphingolipids (GSLs), including gangliosides, interact with specific membrane proteins, such as growth factor receptors, integrins, tetraspanins (TSPs), and nonreceptor cytoplasmic kinases (e.g., Src family kinases and small G proteins), to form glycosynaptic microdomains controlling GSL-dependent or -modulated cell adhesion, growth, and motility (for review, see refs. 1-3).Our previous studies indicate the following: (i) Ganglioside the GM3/TSP CD9 complex interacts with integrin ␣3␤1 or ␣5␤1 and inhibits motility of CD9-expressing tumor cells (4, 5). (ii) The GM3/CD9/CD81 complex inhibits tyrosine kinase associated with fibroblast growth factor receptor (FGFR) (6) and blocks functional interaction of integrins with FGFR (7). (iii) Enhancement of GM3 or CD9 level in bladder cancer cell line YTS-1 causes reversion to normal phenotype, whereby Src kinase activity is strongly inhibited (8).In contrast to these previous studies, focused on GM3-CD9 interaction that inhibits tumor cell motility, our recent studies (9) addressed the functional role of t...

“…They are major components of membrane microdomains known as "lipid rafts" (22) and are important players in cell signaling (23) and cell-cell interaction (24). By influencing membrane properties and/or by direct interaction with membrane proteins, gangliosides modulate the activity of many tyrosine kinase (25)(26)(27)(28) and neurotransmitter receptors (29), ion channels (30,31), and downstream cell signaling pathways. In addition, gangliosides regulate axon-myelin communication and the maintenance of myelinated axons in the adult central and peripheral nervous systems (32)(33)(34).…”

mentioning

confidence: 99%

Ganglioside GM1 induces phosphorylation of mutant huntingtin and restores normal motor behavior in Huntington disease mice

Pardo

Maglione

Alpaugh

et al. 2012

146

143

Huntington disease (HD) is a progressive neurodegenerative monogenic disorder caused by expansion of a polyglutamine stretch in the huntingtin (Htt) protein. Mutant huntingtin triggers neural dysfunction and death, mainly in the corpus striatum and cerebral cortex, resulting in pathognomonic motor symptoms, as well as cognitive and psychiatric decline. Currently, there is no effective treatment for HD. We report that intraventricular infusion of ganglioside GM1 induces phosphorylation of mutant huntingtin at specific serine amino acid residues that attenuate huntingtin toxicity, and restores normal motor function in already symptomatic HD mice. Thus, our studies have identified a potential therapy for HD that targets a posttranslational modification of mutant huntingtin with critical effects on disease pathogenesis.H untington disease (HD) is an inherited neurodegenerative monogenic disorder caused by the expansion of a polyglutamine stretch beyond 36 residues in the amino-terminal domain of huntingtin (Htt), a protein expressed in most tissues and cells. The mutation causes huntingtin to acquire toxic conformation/s and to affect neuronal function and viability. Medium-sized spiny neurons in the corpus striatum are most affected, but neurodegeneration also occurs in the cerebral cortex and, to a minor extent, in other brain areas, resulting in motor and psychiatric symptoms, as well as cognitive decline.The cellular and molecular mechanisms underlying HD pathogenesis are complex. Both loss and gain of function of mutant huntingtin contribute to cause a wide array of neuronal dysfunctions affecting cell signaling, gene transcription, axonal transport, cell and mitochondrial metabolism as well as neurotransmission (1).In recent years, a breakthrough in HD research has been the discovery that posttranslational modifications of mutant Htt are crucial modulators of mutant Htt toxicity (2-4). Phosphorylation at various serine residues prevents cleavage of mutant huntingtin into more toxic fragments, decreases neural cell death in vitro (5-10), and/or restores Htt functions that are compromised by the mutation (8, 11). The most dramatic effects have been described for huntingtin phosphorylation at serine 13 and serine 16. These two amino acid residues are part of the highly conserved amino-terminal "N17" domain of huntingtin, a domain that regulates huntingtin intracellular localization and association to cellular membranes (12, 13), as well as kinetics of mutant huntingtin aggregation (14,15). Phosphomimetic mutations of serine 13 and serine 16 by aspartic or glutamic acid substitution (S13D and S16D or S13E and S16E) decrease the toxicity of mutant huntingtin fragments in vitro (10, 16). In line with these studies, expression of a phosphomimetic (S13D and S16D) mutant form of expanded full-length huntingtin in a BACHD transgenic mouse model was shown to result in a normal phenotype, with no detectable signs of HD pathology by 12 mo (17).These findings suggest that pharmacological interventions that modulate cell sig...