Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by Menelas N. Pangalos
Total Records ( 2 ) for Menelas N. Pangalos
  Gareth Williams , Andrew Wood , Emma- Jane Williams , Ying Gao , Mary L. Mercado , Alan Katz , Diane Joseph-McCarthy , Brian Bates , Huai- Ping Ling , Ann Aulabaugh , Joe Zaccardi , Yuhong Xie , Menelas N. Pangalos , Frank S. Walsh and Patrick Doherty
  Gangliosides are key players in neuronal inhibition, with antibody-mediated clustering of gangliosides blocking neurite outgrowth in cultures and axonal regeneration post injury. In this study we show that the ganglioside GT1b can form a complex with the Nogo-66 receptor NgR1. The interaction is shown by analytical ultracentrifugation sedimentation and is mediated by the sialic acid moiety on GT1b, with mutations in FRG motifs on NgR1 attenuating the interaction. One FRG motif was developed into a cyclic peptide (N-AcCLQKFRGSSC-NH2) antagonist of GT1b, reversing the GT1b antibody inhibition of cerebellar granule cell neurite outgrowth. Interestingly, the peptide also antagonizes neurite outgrowth inhibition mediated by soluble forms of the myelin-associated glycoprotein (MAG). Structure function analysis of the peptide point to the conserved FRG triplet being the minimal functional motif, and mutations within this motif inhibit NgR1 binding to both GT1b and MAG. Finally, using gene ablation, we show that the cerebellar neuron response to GT1b antibodies and soluble MAG is indeed dependent on NgR1 function. The results suggest that gangliosides inhibit neurite outgrowth by interacting with FRG motifs in the NgR1 and that this interaction can also facilitate the binding of MAG to the NgR1. Furthermore, the results point to a rational strategy for developing novel ganglioside antagonists.
  Karina J. Vargas , Miho Terunuma , Judith A. Tello , Menelas N. Pangalos , Stephen J. Moss and Andres Couve
  The efficacy of synaptic transmission depends on the availability of ionotropic and metabotropic neurotransmitter receptors at the plasma membrane, but the contribution of the endocytic and recycling pathways in the regulation of γ-aminobutyric acid type B (GABAB) receptors remains controversial. To understand the mechanisms that regulate the abundance of GABAB receptors, we have studied their turnover combining surface biotin labeling and a microscopic immunoendocytosis assay in hippocampal and cortical neurons. We report that internalization of GABAB receptors is agonist-independent. We also demonstrate that receptors endocytose in the cell body and dendrites but not in axons. Additionally, we show that GABAB receptors endocytose as heterodimers via clathrin- and dynamin-1-dependent mechanisms and that they recycle to the plasma membrane after endocytosis. More importantly, we show that glutamate decreases the levels of cell surface receptors in a manner dependent on an intact proteasome pathway. These observations indicate that glutamate and not GABA controls the abundance of surface GABAB receptors in central neurons, consistent with their enrichment at glutamatergic synapses.
 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility