Control Tx/Rx pin with another GPIO pin / sensor

Hello, I am a newbie on raspberry pi. I want to ask about controling Tx/Rx pin using another pin. I want make a project to control Rx pin with ultrasonic sensor. The propose system like this, if the distace > 30 cm, the Rx pin didnt receive any data and if the distance <=30 cm, the ultrasonic sensor will trigger Rx pin to receiver any data from another device. Is it possible ?

If the tx/Rox is being used for serial then the grip can’t just grab/stop it. But you could use the grip to decide or gate any data you may want to send to it