After the charter for a corporation seeking to conduct banking business in Tennessee has been filed with the secretary of state, the incorporators or, if directors have been initially appointed, the directors of the proposed state bank, may call for the payment of the subscriptions. The subscriptions shall be placed into an escrow account. The incorporators or directors, as appropriate, may not remove any funds from the escrow account prior to the issuance of the certificate of authority or upon written approval from the commissioner.