Prohibitin

Prohibitin (PHB) is an evolutionarily conserved protein family composed of the closely related isoforms PHB1 and PHB2, which are predominantly localized to the inner mitochondrial membrane and form a heteromeric complex that preserves mitochondrial integrity and cellular homeostasis^[1][2]. Mechanistically, prohibitins regulate mitochondrial architecture, cristae morphogenesis, mitochondrial dynamics, and quality-control processes, thereby supporting cell survival and metabolic adaptation under stress conditions^[1][3][4]. Beyond mitochondria, PHB1 and PHB2 are distributed in the nucleus and plasma membrane, where they participate in transcriptional regulation and signal transduction pathways that influence proliferation, apoptosis, and cellular differentiation^[2][5]. A key biological distinction between the isoforms is that PHB2 functions as a mitophagy receptor through interaction with LC3 during mitochondrial depolarization, whereas PHB1 is more extensively characterized as a scaffold and signaling regulator associated with transcriptional control and membrane-associated signaling events^[2]. In disease contexts, dysregulated PHB1 and PHB2 expression has been reported in multiple cancers and is linked to tumor cell proliferation, apoptosis, migration, and metastasis through pathways including Raf-MEK-ERK signaling^[2][5]. Experimental studies further demonstrate that prohibitins contribute to neurodegenerative disease models by regulating mitochondrial function, neuronal survival, and mitochondrial quality control^[1][6]. For research applications, small-molecule ligands such as rocaglamide and fluorizoline directly target prohibitin proteins and disrupt PHB-dependent signaling, providing useful pharmacological tools for mechanistic studies and target validation in disease models^[5][2].