Kindling protein (KFP) can undergo irreversible photoconversion from non-fluorescent to stable red fluorescent form upon photoactivation.

Reference:
DM Chudakov, VV Belousov, AG Zaraisky, VV Novoselov, DB Staroverov, DB Zorov, S Lukyanov, KA Lukyanov: Kindling fluorescent proteins for precise in vivo photolabeling. Nature Biotechnology 21 (2003) 191-94.