Michigan Compiled Laws, Chapter 450. Corporations § 450.1535

Sec. 535. (1) An officer elected or appointed by the board may be removed by the board with or without cause. An officer elected by the shareholders may be removed, with or without cause, only by vote of the shareholders, but his authority to act as an officer may be suspended by the board for cause.

(2) The removal of an officer shall be without prejudice to his contract rights, if any. The election or appointment of an officer does not of itself create contract rights.

(3) An officer may resign by written notice to the corporation. The resignation is effective upon its receipt by the corporation or at a subsequent time specified in the notice of resignation.