This entry represents the membrane-bound transcription factor site-2 protease (MBTPS2, also known as S2P) []. MBTPS2 is a membrane-embedded zinc metalloprotease that activates signaling proteins involved in sterol control of transcription and ER stress response []. It cleaves several transcription factors that are type-2 transmembrane proteins within membrane-spanning domains. Its known substrates include sterol regulatory element-binding protein (SREBP) -1, SREBP-2 and forms of the transcriptional activator ATF6 [, ]. Mutations in the MBTPS2 gene cause IFAP syndrome with or without BRESHECK syndrome (IFAPS) and Keratosis follicularis spinulosa decalvans X-linked (KFSDX) [, ]. S2Ps are widely distributed in bacteria and participate in diverse pathways that control functions such as membrane integrity, sporulation, lipid biosynthesis, pheromone production, virulence, and others [].
