Light-induced down-regulation of the rat class 1 dynein-associated protein robl/LC7-like gene in visual cortex.

Dynein and kinesin are the main microtubule-dependent motors that mediate intracellular movement in eukaryotic organisms. We have cloned a full-length cDNA encoding rat dynein light chain protein, robl/LC7-like (class 1), from visual cortex. We found that rat robl/LC7-like gene is highly expressed in neocortex and displays the unusual feature of being rapidly down-regulated by sensory stimulation. This effect was seen at both mRNA and protein levels in visual cortex, being detectable in as little as 45 min after the onset of visual stimulation. Down-regulation by sensory stimulation was also found within ocular dominance columns of area V1 in monocularly deprived monkeys. Our results suggest a high turnover rate of the robl/LC7-like protein and the presence of a repressor mechanism in neurons that is tightly coupled to synaptic stimulation.