High impact information on Omg

• Thus, OMgp is an important inhibitor of neurite outgrowth that acts through NgR and its associated receptor complex [1].
• We show here that a glycosylphosphatidylinositol (GPI)-anchored CNS myelin protein, oligodendrocyte-myelin glycoprotein (OMgp), is a potent inhibitor of neurite outgrowth in cultured neurons [1].
• Cleavage of NgR and other GPI-linked proteins from the cell surface renders axons of dorsal root ganglia insensitive to OMgp [1].
• Three myelin-associated, structurally distinct proteins, Nogo, myelin-associated glycoprotein, and oligodendrocyte myelin glycoprotein, have been implicated in this inhibition [2].
• Overexpression of OMgp alters PDGF signaling in fibroblasts which results in a block of mitogenic signaling [3].

Biological context of Omg

• We obtained two distinct overlapping DNA clones from a mouse genomic library that contain the OMgp gene from mouse (mOMgp) [4].
• The conservation of the nucleotide sequences of the coding, noncoding, and flanking regions of the two genes is remarkable and raises the possibility that the nucleotide sequence may serve a function that is separate from the role of encoding OMgp [4].
• We previously observed that the OMgp gene locus on chromosome 17 could be associated with autism, a developmental disorder [5].
• Using quantitative and semi-quantitative RT-PCR, we studied OMgp gene expression in rat brain during post-natal development [5].
• The OMgp gene, a second growth suppressor within the NF1 gene [3].

Anatomical context of Omg

• Like Nogo-A, OMgp contributes significantly to the inhibitory activity associated with CNS myelin [1].
• The aim of the present study was to characterise the developmental expression of OMgp mRNA in the central nervous system [5].
• We observed a similar profile in oligodendrocyte cultures, in absence of neurones, suggesting that OMgp mRNA expression by oligodendrocytes was independent of axonal influence [5].
• Overexpression of OMgp alters mitogenic signaling in NIH3T3 fibroblasts [3].
• Most of the OMgp in the mouse brain appears to be expressed in diverse groups of neurons, but it is particularly prominent in large projection neurons such as the pyramidal cells of the hippocampus, the Purkinje cells of the cerebellum, motoneurons in the brainstem, and anterior horn cells of the spinal cord [6].

Associations of Omg with chemical compounds

• The oligodendrocyte-myelin glycoprotein is anchored solely in the outer leaflet of the plasma membrane via its glycosylphosphatidylinositol anchor, and through its leucine-rich repeat domain, it likely interacts with other proteins [7].

Other interactions of Omg

• The oligodendrocyte-myelin glycoprotein is a ligand of the neuronal Nogo receptor and a potent inhibitor of neurite outgrowth, but its physiological function remains to be elucidated [7].

Analytical, diagnostic and therapeutic context of Omg

• OMgp is present in a concentration detectable on western blots in the brains of newborn mice, and its concentration gradually increases until day 24 of life [6].
• OMgp mRNA is also present in amounts detectable on northern blots in the brains of newborn mice, and its concentration gradually increases until day 21 of life, after which the concentration diminishes a little [6].
• Based on its detergent solubility profile and membrane fractionation using established ultracentrifugation procedures, we conclude that the oligodendrocyte-myelin glycoprotein is a lipid raft component that is closely associated with the axolemma [7].
• OMgp purified by a different procedure from both mouse and human myelin behaves identically in all bioassays tested [8].
• In this study, immunohistochemistry, western blots, in situ hybridization, and northern blots were used to determine the distribution of OMgp in the mouse brain [6].

References