Johnston filed his letter of intent Friday with the Alaska Public Offices Commission, a first step needed to begin campaigning.
The letter doesn't specify an office, though Johnston's manager, Tank Jones, has said Johnston's interested in a run for mayor or City Council. He did not immediately return a message Monday.
Earlier this month, Jones confirmed that Johnston planned to run for office as part of a reality TV show.
Johnston has had a prickly relationship with the Palin family since the birth of his son, Tripp. He and Bristol Palin recently broke off a short-lived engagement.
The filing was first reported by TMZ.com.




