Keratin, type II cytoskeletal 8 (K8)

Keratin 8 (K8) is a type II intermediate filament protein found predominantly in simple epithelial cells, where it forms heterodimers with keratin 18 to maintain cellular structure and integrity[2][3][4][7]. Beyond mechanical support, K8 modulates key signaling pathways, protein trafficking (notably within ER quality control and ER-associated degradation complexes), and cellular stress responses[1][5]. It is highly expressed in various epithelial-derived cancers and is a valuable immunohistochemical marker for tumor identification and classification[3][4]. Recent evidence suggests targeting K8-associated complexes may offer therapeutic strategies for protein misfolding disorders such as alpha-1 antitrypsin deficiency[1]. K8’s functional diversity underscores its importance as both a biomarker and a potential therapeutic target, but also raises safety challenges due to its essential physiological roles.

Other names

CK-8Cytokeratin-8Keratin-8CYK8Type-II keratin Kb8

Small molecule-induced modulation of scaffolding and retention functions within ERAD complexes; Inhibition of substrate dislocation (e.g., VCP/p97 inhibitors affecting degradation pathways in ER)