Neuroligin 3 is a vertebrate gliotactin expressed in the olfactory ensheathing glia, a growth‐promoting class of macroglia

Abstract

The molecular mechanisms that drive glia-glial interactions and glia-neuronal interactions during the development of the nervous system are poorly understood. A number of membrane-bound cell adhesion molecules have been shown to play a role, although the precise nature of their involvement is unknown. One class of molecules with cell adhesive properties used in the nervous system is the serine-esterase-like family of transmembrane proteins. A member of this class, a glia-specific protein called gliotactin, has been shown to be necessary for the development of the glial sheath in the peripheral nervous system of Drosophila melanogaster. Gliotactin is essential for the development of septate junctions in the glial sheath of individual and neighboring glia. Mutations that remove this protein result in paralysis and eventually death due to a breakdown in the glial-based blood-nerve barrier. To study the role of gliotactin during vertebrate nervous system development, we have isolated a potential vertebrate gliotactin homologue from mice and rat and found that it corresponds to neuroligin 3. Using a combination of RT-PCR and immunohistochemistry, we have found that neuroligin 3 is expressed during the development of the nervous system in many classes of glia. In particular neuroligin 3 is expressed in the olfactory ensheathing glia, retinal astrocytes, Schwann cells, and spinal cord astrocytes in the developing embryo. This expression is developmentally controlled such that in postnatal and adult stages, neuroligin 3 continues to be expressed at high levels in the olfactory ensheathing glia, a highly plastic class of glia that retain many of their developmental characteristics throughout life.

Genes Associated with Adult Axon Regeneration Promoted by Olfactory Ensheathing Cells: A New Role for Matrix Metalloproteinase 2

“…1 A) and Western blotting ( Fig. 1 B) (Ramon-Cueto and Nieto-Sampedro, 1992;Perroteau et al, 1998;Pollock et al, 1999;Gilbert et al, 2001;Moreno-Flores et al, 2003b). Proteins such as S100␤, p75 NTR , 3PGDH, APP, and ErbB2 were expressed similarly in all three OEC populations.…”

Characterization of the neuroligin gene family expression and evolution in zebrafish

“…Neuroligin proteins have been identified in different species from invertebrates to human (Ichtchenko et al, 1995;Bolliger et al, 2001;Gilbert et al, 2001;Kwon et al, 2004;Biswas et al, 2008). The mouse genome encodes four Neuroligin family members while five different genes (NLGN1, NLGN2, NLGN3, NLGN4X, and NLGN4Y) are present in the human genome (Ichtchenko et al, 1996;Bolliger et al, 2001Bolliger et al, , 2008Paraoanu et al, 2006).…”

“…Neuroligin 1 expression is mainly restricted to the CNS, while Neuroligins 2-4 present a broader expression pattern (Song et al, 1999;Philibert et al, 2000;Bolliger et al, 2001;Gilbert et al, 2001;Kang et al, 2004;Suckow et al, 2008). Some lines of evidence suggest that the expression of Neuroligins may differ between species.…”

Gliotactin and Discs large form a protein complex at the tricellular junction of polarized epithelial cells inDrosophila

“…Gliotactin is homologous to the vertebrate Neuroligins (Gilbert et al, 2001;Gilbert and Auld, 2005). All members of this family contain a highly conserved extracellular serine esterase-like domain, which lacks one of three residues necessary for enzymatic function.…”