Recombinant Human Keratin, type I cytoskeletal 18 (KRT18)

Function

Structural component of intermediate filaments in simple epithelial cells. Forms obligate heteropolymers with a type II keratin KRT8, mechanical stability and resilience to epithelial cells (PubMed:15529338, PubMed:26823019). KRT8/KRT18 filaments are involved in ARHGEF40-mediated actin stress fiber formation and tensional force-induced stress fiber formation and reinforcement (PubMed:26823019). Organization and orientation of KRT8/KRT18 filaments are responsible for the properly elongated morphology of epithelial tubules (By similarity). Also acts downstream of ROCK kinase activation as part of a positive feedback mechanism in response to cellular mechanical stress loading (PubMed:26823019). Involved in the uptake of thrombin-antithrombin complexes by hepatic cells (By similarity). When phosphorylated, plays a role in filament reorganization (PubMed:7523419, PubMed:8522591, PubMed:9298992, PubMed:9524113). Involved in the delivery of mutated CFTR to the plasma membrane (PubMed:15529338, PubMed:16424149). Involved in interleukin-6 (IL-6)-mediated barrier protection (PubMed:17213200)

Subcellular Location

Nucleus matrix; Cytoplasm, perinuclear region; Nucleus, nucleolus; Cytoplasm

Disease Association

Cirrhosis (CIRRH) : A liver disease characterized by severe panlobular liver-cell swelling with Mallory body formation, prominent pericellular fibrosis, and marked deposits of copper. Clinical features include abdomen swelling, jaundice and pulmonary hypertension. [The disease is caused by variants affecting the gene represented in this entry]

Tissue Specificity

Expressed in colon, placenta, liver and very weakly in exocervix. Increased expression observed in lymph nodes of breast carcinoma

Subunit

(Microbial infection) Interacts with hepatitis C virus/HCV core protein

• Oshima R.G. et al. Comparison of mouse and human keratin 18: a component of intermediate filaments expressed prior to implantation. — Differentiation (1986)
• Kim J.W. et al. Identification of a cell proliferation-inducing gene. (SEP-)
• Kalnine N. et al. Cloning of human full-length CDSs in BD Creator(TM) system donor vector. (OCT-)
• Suzuki Y. et al. PubMed: CI-5AVBODINQ93DF (APR-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Kulesh D.A. et al. Cloning of the human keratin 18 gene and its expression in nonepithelial mouse cells. — Mol. Cell. Biol. (1988)
• Leube R.E. et al. Cytokeratin expression in simple epithelia. III. Detection of mRNAs encoding human cytokeratins nos. 8 and 18 in normal and tumor cells by hybridization with cDNA sequences in vitro and in situ. — Differentiation (1986)
• Romano V. et al. Cytokeratin expression in simple epithelia. I. Identification of mRNA coding for human cytokeratin no. 18 by a cDNA clone. — Differentiation (1986)