High impact information on Ncam2

• Differential function of RNCAM isoforms in precise target selection of olfactory sensory neurons [1].
• Analyses of transgenic mice that ectopically express RNCAM in NADPH diaphorase-positive OSNs show that the postulated function of RNCAM in mediating zone-specific segregation of axons is unlikely [1].
• Both Gpi-anchored and transmembrane-bound RNCAM isoforms are localized on axons in the nerve layer, while the transmembrane-bound RNCAM is the predominant isoform on axon terminals within glomeruli [1].
• The phenotype specific for Gpi-anchored RNCAM is suppressed in mice overexpressing both isoforms, which suggests that two distinct RNCAM isoform-dependent activities influence segregation of OR-defined axon subclasses [1].
• We describe here the cloning of mouse complementary DNAs encoding a novel protein, Rb-8 neural cell adhesion molecule (RNCAM), with a predicted extracellular region of five immunoglobulin C2-type domains followed by two fibronectin type III domains [2].

Biological context of Ncam2

• Alternative splicing is likely to generate two RNCAM isoforms, which are differently attached to the cell membrane [2].
• These expression patterns thus render RNCAM the first described cell adhesion molecule with a potential regulatory role in formation of selective axonal projections important for olfactory sensory information coding [2].

Associations of Ncam2 with chemical compounds

• We have identified NADPH diaphorase activity as being an independent marker for RNCAM-negative axons [1].
• Here we identified OCAM (R4B12 antigen), an axonal surface glycoprotein expressed by subsets of both olfactory and vomeronasal axons in a zone-specific manner [3].

Regulatory relationships of Ncam2

• Intriguingly, RNCAM likewise is expressed in subsets of olfactory and vomeronasal neurons with topographically defined axonal projections [2].

Other interactions of Ncam2

• The spatial expression RNCAM corresponds precisely to that of certain odorant receptor expression zones of the olfactory epithelium [2].
• VN subpopulations do not show complementary patterns of RNCAM and NQO1 immunoreactivity, instead both genes are co-expressed in apical VN neurons that project to the rostral AOB [4].

Analytical, diagnostic and therapeutic context of Ncam2

• Immunohistochemistry and in situ hybridization analyses show non-overlapping expression of NQO1 and the Rb8 neural cell adhesion molecule (RNCAM/OCAM) in OE and axon terminals within glomeruli of the OB [4].

References