Native and Recombinant DM-GRASP Selectively Support Neurite Extension from Neurons That Express GRASP

Abstract

DM-GRASP (GRASP) is an integral membrane glycoprotein expressed on a restricted set of axons in the developing chick nervous system. We demonstrate that purified GRASP supports neurite extension from the subpopulation of neurons that express GRASP. Sensory, sympathetic, and ciliary neurons express GRASP and extend neurites on a GRASP substrate. In contrast, tectal, diencephalic, and retinal cells express GRASP at a very low level, if at all, and do not extend neurites on a GRASP substrate. Moreover, as GRASP is downregulated on sensory neurons during development, they lose the capacity to extend neurites on a GRASP substrate. Recombinant GRASP produced in a baculovirus expression system is biochemically and functionally identical to GRASP purified from embryonic chick brain. The finding that GRASP selectively supports neurite extension supports the hypothesis that it mediates selective fasciculation via a homophilic binding mechanism.

Translation of the cell adhesion molecule ALCAM in axonal growth cones – regulation and functional importance

“…The IgSF-CAM ALCAM (for activated leukocyte cell adhesion molecule, previously also termed DM-GRASP, SC1, BEN, CD166 or MEMD) plays a role in cell adhesion (Burns et al, 1991;Tanaka et al, 1991), neuronal migration and differentiation (Stephan et al, 1999;Heffron and Golden, 2000), axon growth (Pollerberg and Mack, 1994;DeBernardo and Chang, 1995) and axonal pathfinding (Avci et al, 2004;Weiner et al, 2004). ALCAM interacts homophilically, i.e.…”

Molecular Isolation and Characterization of a Soluble Isoform of Activated Leukocyte Cell Adhesion Molecule That Modulates Endothelial Cell Function

“…In addition, ALCAM has been detected in a variety of cell types where it participates in heterophilic interactions with unknown ligands as well as homophilic interactions, suggesting that ALCAM has varied functions (8,9). In fact, BEN/ SC1/DM-GRASP, a chicken homologue of ALCAM, is expressed in the nervous systems and plays a role in axogenesis, neurite elongation, and synapse formation (2,10,11). Although AL-CAM is expressed in a variety of cell types and tissues, it is certainly expressed in subsets of cells involved in dynamic growth and migration, including developing neuronal cells, hematopoietic cells.…”

The cell adhesion molecule NrCAM is crucial for growth cone behaviour and pathfinding of retinal ganglion cell axons

“…L1 is capable of promoting RGC axon growth by itself (Morales et al, 1996). DM-GRASP and F3/F11/Contactin promote axon growth of other neuron types, but not of RGCs (DeBernardo and Chang, 1995;Treubert and Brummendorf, 1998), indicating a differential use of receptors or intracellular signalling pathways in various neuron types.…”