NRCAM (neuronal cell adhesion molecule)

	Cartoon of the distribution of NrCAM exons, including those used in most transcripts (open boxes) and those that are alternatively spliced (filled boxes). Most exons are conserved in human, mouse and rat. Exons 1b and 33 have not been identified in humans. The candidate alternatively transcribed exons produce the shorter rat and human isoforms are shown in the bottom two rows. (Rows 3-8) NrCAM clones (Nc)1, 3, 6, 7, 14, 17 that represent splice variant isoforms identified in rat brain cDNAs. (Rows 9-10) Shorter NrCAM gene product expressed isoforms that are identified from ESTs in rat and human databases (from Ishiguro et al., 2006).
Description	The NrCAM gene is about 316 kb in length, consisting of 34 exons.
Transcription	NrCAM is transcribed from a single gene and the mRNA may be alternatively processed into multiple species (Grumet et al., 1991). Different transcripts of NRCAM are produced by alternative splicing of exons 10, 19 and 27-29. There are three main alternative spliced mRNA according to Entrez: variant A - NM_001037132.1, variant B - NM_005010.3, variant C - NM_001037133.1.

	Cartoon of NrCAM's structure with fibronectin, immunoglobulin, transmembrane, and intracellular (C-terminal) domains indicated. Arrows indicate sites where splice variants encode additional inserted additional amino acids. These NrCAM structures are conserved in human, mouse, and rat. (from Ishiguro et al., 2006).
Description	NrCAM is a cell surface protein of the immunoglobulin superfamily, L1/neurofascin/NgCAM subgroup. The molecule is 200-220kDa transmembrane protein, which contains 5 fibronectin type-III domains, 6 Ig-like C2-type (immunoglobulin-like) domains in the extracellular region and a highly conserved cytoplasmic tail. (Grumet et al., 1991; Kayyem et al., 1992; Lane et al., 1996). Human NrCAM has few alternatively spliced regions: AE19 adds 19 amino acids to the region between Ig domain 2 and 3; AE10 lies clearly between Ig domain 6 and the beginning of the Fn repeats; AE10K2 encompasses part of the G strand of Ig 5 and most of the A strand of Ig 6; AE12 affects the G strand of Fn III domain 4; AE93 corresponds to the entire Fn type III domain (Grumet et al.,1991; Lane et al., 1996; Wang et al., 1998).
Expression	Central and peripheral nervous system, and other tissues, endothelial cells, and certain tumor cell lines and human cancers including pancreatic cancer, melanoma, renal and colon carcinoma, adrenal gland, placenta, thyroid and testis (Wang et al., 1998; Glienke et al, 2000; Dhodapkar et al., 2001; Aitkenhead et al, 2002; Conacci-Sorrell et al., 2002). Nervous system: NrCAM is expressed in structures in the developing brain. In the floor plate NrCAM has been implicated in axonal guidance trough interaction with TAG-1/axonin-1 (Lustig et al., 2001). Moreover, NrCAM induces neurite outgrowth from dorsal root ganglia neurons. It also operates as a receptor for several different neuronal recognition molecules. NrCAM protein promotes directional signaling during nervous system development in several different regions as the spinal cord, the visual system, and the cerebellum (Lustig et al., 2001; Hutcheson et al., 2004).
Localisation	Various cell compartments: external side of plasma membrane, integral to plasma membrane, neuron projection, cytoplasm, nucleus.
Function	NrCAM is engaged in such biological processes as axonal fasciculation, cell-cell adhesion, central nervous system development, clustering of voltage-gated sodium channels, neuron migration, positive regulation of neuron differentiation, regulation of axon extension, and synaptogenesis. It also may play a role in the molecular assembly of the nodes of Ranvier. NrCAM effects are also linked with different recognition processes and signal transduction pathways regulating cell differentiation, proliferation, or migration (Gumbiner, 1996; Cavallaro and Christofori, 2004).
Homology	- NRCAM, neuronal cell adhesion molecule, Homo sapiens - NRCAM, neuronal cell adhesion molecule, Bos taurus - Nrcam, neuron-glia-CAM-related cell adhesion molecule, Mus musculus - Nrcam, neuron-glia-CAM-related cell adhesion molecule, Rattus norvegicus - NRCAM, neuronal cell adhesion molecule, Gallus gallus - si:dkey-240a12.1, si:dkey-240a12.1, Danio rerio - Nrg, Neuroglian, Drosophila melanogaster - AgaP_AGAP000720, AGAP000720-PA, Anopheles gambiae - lad-2, L1 CAM ADhesion molecule homolog, Caenorhabditis elegans - NRCAM, neuronal cell adhesion molecule, Pan troglodytes - LOC475881, similar to Neuronal cell adhesion m..., Canis lupus familiaris.

Search in all EBI   NCBI

For comments and suggestions or contributions, please contact us