The function of KRT1 (keratin 1, ENSG00000167768) is as follows. Structural component of intermediate filaments in suprabasal keratinocytes of stratified epithelia. Forms heteropolymers with a type I keratin, assembling into keratin intermediate filament networks that provide mechanical strength and structural stability to differentiating epidermal cells (PubMed:1381288). May regulate the activity of kinases such as PKC and SRC by interacting with integrin beta-1 (ITB1) and the receptor of activated protein C kinase 1 (RACK1) (PubMed:17956333, PubMed:21544310). In complex with C1QBP, acts as a high-affinity receptor for kininogen-1 (HMWK) (PubMed:21544310). {ECO:0000269|PubMed:1381288, ECO:0000269|PubMed:17956333, ECO:0000269|PubMed:21544310}.