mover and shaker

One who wields power and influence in a sphere of activity: “the importance of hanging out with the movers and shakers of the art world” (Richard Colvin).

Individual who has a dramatic impact on an organization or a series of events. For example, an individual may be known as a mover and shaker in a particular business activity because of his ability to get things done quickly and successfully.

A person who wields power and influence in a particular activity or field, as in He's one of the movers and shakers in the art world. At first the two nouns referred specifically to God, alluding to the belief that a divine force was responsible for all events. The current usage refers only to human beings. [Second half of 1800s]

The noun has one meaning:

Meaning #1: a person who wields power and influence
  Synonym: shaker