The interjurisdictional planning commission of a municipality shall consist of six members. Three members shall be chosen by the mayor of the municipality with the approval of the council from the membership of the municipality's planning commission. Three members shall be chosen by the county board of the county within which the municipality exercises zoning jurisdiction under the circumstances specified in section 19-930. The three members chosen by the county board shall be members of the county planning commission as described in section 23-114.01. Members of the interjurisdictional planning commission shall serve without compensation and without reimbursement for expenses incurred pursuant to carrying out sections 19-930 to 19-933 for terms of one year. Members shall hold office until their successors are appointed and qualified. Vacancies shall be filled by appointment by the body which appointed the member creating the vacancy.