The lieutenant governor may designate a head of a principal executive department, or more than one such officer in the alternative, who shall temporarily be custodian of the state seal and perform the authenticating functions of the lieutenant governor during such time as the lieutenant governor succeeds to the office of governor, acts as governor, is absent from the state, or otherwise is not available at the state capital to perform the above authenticating functions. The designation shall be in writing, signed by the lieutenant governor, and filed in the office of the lieutenant governor. The designation is effective until revoked by a later designation executed and filed in the same manner.