A device is provided for sealing an opening made in a structure, including a fixed panel in which an opening is defined, and at least one sliding panel, including: two shuttles respectively guided in two guiding rails mounted and/or formed on the surface of the fixed panel facing the inside of the vehicle and a frame supporting at least two guiding pins respectively engaging with each one of the shuttles. The shuttles include guides for guiding the pins, enabling a transverse movement of the frame relative to the shuttles. An actuator acts directly or indirectly on the shuttles in order to move the latter in the rails, causing the sliding panel to move in a direction perpendicular to the plane of the fixed panel. The device also synchronizes the actuator so as to synchronize the movement of the shuttles.