Is there any mechanism or specific protein which helps lizards to regrow their tail? Can the mechanism of regeneration be used in humans to regenerate our limbs? Is there any other animal which has this kind of ability?
Actually there are some studies to find out your answer. Some of the studies claim that they have found a special enzyme and some say micro RNAs give salamanders the capacity of regeneration. But until now, humans couldn't use salamander's regenerative ability. Maybe you would like to know there is a mammal (african spiny mouse) with special regenerative capacities which include regeneration of its skin and cartilage without scarring.
For further studies I recommend searching "salamander and regeneration", "african spiny mouse and regeneration" in pubmed ;)