Structure and function of a receptor for neurite outgrowth factor

• Published in: Japanese Journal of Pharmacology Vol. 58; no. suppl.1; p. 20
• Main Authors: Miki, Naomasa, Taniura, Hideo, Taira, Eiichi, Kato, Susumu
• Format: Journal Article
• Language: English
• Published: The Japanese Pharmacological Society 1992
• DOI: 10.1016/S0021-5198(19)37719-4
• ISSN: 0021-5198

Neurons extend their neurites to their target cells during development and form synapses. We have isolated a neurite outgrowth factor, its receptor and their cDNA clones, and discuss here how these molecules are involved in the synaptic formation and regeneration of nervous system. 1. Neurite outgrowth factor (NOF)：NOF is an extracelluar matrix protein (72 kDa, subunit 21 kDa) which promotes neurites from chick ciliary and retinal neurons and has a homology with laminin B1 chain. Neurons lose their neuritic responsibility to NOF with age, suggesting a possibility that NOF receptor decreases with age. 2. NOF receptor (NOFR)：We have isolated NOFR from chick muscle membranes by using inhibition assay and ligand binding assay. The NOFR is a membrane protein of 82 kDa, which is distributed in particular regions in the retina and the brain during development. Anti-NOFR completely blocked the neurite extension by NOF from retinal and cerebellar explants, indicating that neurite outgrowth by NOF occurs through recognizing a specific receptor of 82 kDa. Quantitative decrease in NOFR in the embryonic retina was observed after day 11 by ligand bot and immunoblot and its decrease was parallel well with age-dependent reduction of NOF-induced neurite outgrowth of embryonic retinas. In developing cerebellum, NOFR appeared only in the external granular layer at day 10-12, but markedly decreased after day 18, suggesting that NOFR is involved in the cellular migration and synapse formation in the cerebellum. These data suggest that the decrease in the NOFR expression in neurons with age results in the loss of ability for adult neurons to regenerate.