KRT18

KRT18 Full Name

keratin 18

KRT18 Introduction

KRT18, or keratin 18, is a type I intermediate filament protein that is predominantly expressed in simple epithelial tissues, where it forms heteropolymers with its type II partner keratin 8. As a core component of the cytoskeletal network, KRT18 provides mechanical stability and structural integrity to epithelial cells while also contributing to cellular organization and polarity. Beyond its structural role, keratin 18 is increasingly recognized as a dynamic protein involved in intracellular signaling and stress responses. Its expression pattern and post-translational modifications reflect epithelial differentiation status and cellular health, making KRT18 a widely used marker in cell biology and pathology.

Figure 1. Keratin 18 induces proliferation, migration, and invasion in gastric cancer via the MAPK signalling pathway.(Sources:Wang PB, et al.; 2021)

Functionally, KRT18 supports epithelial resilience by protecting cells from mechanical stress and apoptosis. During cellular stress or programmed cell death, KRT18 undergoes site-specific phosphorylation and caspase-mediated cleavage, generating fragments that serve as indicators of epithelial apoptosis. These modifications influence interactions with signaling molecules, chaperones, and organelles, linking the intermediate filament network to pathways regulating cell survival, protein trafficking, and mitochondrial function. Experimental studies demonstrate that loss or mutation of KRT18 disrupts filament organization, increases susceptibility to stress-induced injury, and alters epithelial barrier function, highlighting its essential role in maintaining tissue homeostasis.

Clinically, KRT18 has important diagnostic and disease relevance. Elevated levels of cleaved KRT18 fragments in blood are established biomarkers of epithelial cell apoptosis and are used to monitor liver injury, non-alcoholic steatohepatitis, and drug-induced toxicity. Mutations or altered expression of KRT18 are associated with liver diseases, including cryptogenic cirrhosis and chronic hepatitis, reflecting impaired cytoskeletal stability in hepatocytes. In oncology, aberrant KRT18 expression is observed in multiple carcinomas and is widely used in tumor classification and prognosis, where its presence indicates epithelial origin and disease progression. These clinical associations underscore KRT18's value as both a functional cytoskeletal protein and a translational biomarker in epithelial pathology, toxicology, and cancer research.

Alternate Names for KRT18

KRT18; keratin 18, type I; K18; CYK18; keratin, type I cytoskeletal 18; CK-18; keratin-18; cytokeratin 18; cytokeratin-18; cell proliferation-inducing protein 46; cell proliferation-inducing gene 46 protein; Cytokeratin 18

• Immunohistochemistry Antibodies for Pathology
• Immunohistochemistry Antibodies for Pathology

• 1. Wang PB, et al.; Keratin 18 induces proliferation, migration, and invasion in gastric cancer via the MAPK signalling pathway. Clin Exp Pharmacol Physiol. 2021, 48(1):147-156.