NCAM1
Description
The NCAM1 (neural cell adhesion molecule 1) is a protein-coding gene located on chromosome 11.
Neural cell adhesion molecule (NCAM), also called CD56, is a homophilic binding glycoprotein expressed on the surface of neurons, glia and skeletal muscle. Although CD56 is often considered a marker of neural lineage commitment due to its discovery site, CD56 expression is also found in, among others, the hematopoietic system. Here, the expression of CD56 is mostly associated with, but not limited to, natural killer cells. CD56 has been detected on other lymphoid cells, including gamma delta (γδ) Τ cells and activated CD8+ T cells, as well as on dendritic cells. NCAM has been implicated as having a role in cell–cell adhesion, neurite outgrowth, synaptic plasticity, and learning and memory.
== Forms, domains and homophilic binding == NCAM is a glycoprotein of Immunoglobulin (Ig) superfamily. At least 27 alternatively spliced NCAM mRNAs are produced, giving a wide diversity of NCAM isoforms. The three main isoforms of NCAM vary only in their cytoplasmic domain:
NCAM-120kDa (GPI anchored) NCAM-140kDa (short cytoplasmic domain) NCAM-180kDa (long cytoplasmic domain) The extracellular domain of NCAM consists of five immunoglobulin-like (Ig) domains followed by two fibronectin type III (FNIII) domains. The different domains of NCAM have been shown to have different roles, with the Ig domains being involved in homophilic binding to NCAM, and the FNIII domains being involved signalling leading to neurite outgrowth. Homophilic binding occurs between NCAM molecules on opposing surfaces (trans-) and NCAM molecules on the same surface (cis-)1.
NCAM1 is a cell adhesion molecule essential for neuron-neuron adhesion, neurite fasciculation, and neurite outgrowth.
NCAM1 is also known as CD56, MSK39, NCAM.
