A Phylogenetic Analysis of the L1 Family of Neural Cell Adhesion Molecules

作者：Mualla Rula; Nagaraj Kakanahalli; Hortsch Michael^*

来源：Neurochemical Research, 2013, 38(6): 1196-1207.

DOI：10.1007/s11064-012-0892-0

• Cell adhesion molecules
• L1-type CAMs
• Evolution
• Gene duplication

L1-type genes form one of several distinct gene families that encode adhesive proteins, which are predominantly expressed in developing and mature metazoan nervous systems. These proteins have a multitude of different important cellular functions in neuronal and glial cells. L1-type gene products are transmembrane proteins with a characteristic extracellular domain structure consisting of six immunoglobulin and three to five fibronectin type III protein folds. As reported here, L1-type proteins can be identified in most metazoan phyla with the notable exception of Porifera (sponges). This puts the origin of L1-type genes at a point in time when primitive cellular neural networks emerged, approximately 1,200 to 1,500 million years ago. Subsequently, several independent gene duplication events generated multiple paralogous L1-type genes in some phyla, allowing for a considerable diversification of L1 structures and the emergence of new functional features and molecular interactions. One such evolutionary newer feature is the appearance of RGD integrin-binding motifs in some vertebrate L1 family members.

• 出版日期2013-6