"At that point we realized the potential significance of lynx1," Miwa said. "Bungarotoxin was known to bind to acetylcholine receptors, so if lynx1 could bind to these receptors too, it might be important for brain signaling."
Ines Ibanez-Tallon, an HHMI associate in Heintz's lab, localized the nerve cell receptors with which lynx1 interacts, and showed that the distribution of these receptors is similar to that of acetylcholine receptors in the cerebellum, a region of the brain involved in controlling motion and motor learning.
Additional collaborators in Lorna Role's laboratory at Columbia University tested lynx1's effect on frog eggs (or oocytes) that had been injected with acetylcholine receptors. Miwa said the eggs' acetylcholine response was 30 percent larger after bathing them with lynx1, suggesting that lynx1 might enhance the action of acetylcholine. By contrast, its cousin, alpha-bungarotoxin, interferes with acetylcholine's activity. But many drugs that affect the brain have been found to generate effects opposite to those of similar substances produced by brain tissue, Heintz said.
Acetylcholine receptors are thought to be involved in memory and in the
pathogenesis of Alzheimer's disease, where loss of inputs from acetylcholine
neurons is a hallmark of the disease. "If lynx1 acts in the whole animal like it
does in cells, then the structure of the p
Contact: Jim Keeley
Howard Hughes Medical Institute