The Department of Finance shall be headed by, and shall be under the direction, supervision and control of, an officer who shall be known and designated as the Director of Finance. The Director of Finance shall be the chief financial officer of the state and the advisor of the Governor and of the Legislature in financial matters, and he shall at all times be charged with protecting the financial interests of the state. He shall be responsible to the Governor for the administration of the Department of Finance. The Director of Finance shall be appointed and hold office at the pleasure of the Governor. Vacancies for any reason shall be filled in the same manner as original appointments are made. Before entering upon the discharge of his duties, the Director of Finance shall take the constitutional oath of office. The Director of Finance shall devote full time to his office and shall not hold another office under the government of the United States, or under any other state, or of this state or any political subdivision thereof, during his incumbency in such office, and he shall not hold any position of trust or profit or engage in any occupation or business, the conduct of which shall interfere or be inconsistent with the performance of his duties as Director of Finance.