KRT31 KRT31 Keratin, type I cuticular Ha1 is a protein that in humans is encoded by the "KRT31" gene. The protein encoded by this gene is a member of the keratin gene family. As a type I hair keratin, it is an acidic protein which heterodimerizes with type II keratins to form hair and nails. The type I hair keratins are clustered in a region of chromosome 17q12-q21 and have the same direction of transcription. Model organisms have been used in the study of KRT31 function. A conditional knockout mouse line called "Krt31" was generated at the Wellcome Trust Sanger Institute.
Hair cell fish have been found to regenerate, their ability has been studied at length. In addition, lateral line hair cells, which have a mechanotransduction function, have been shown to regrow in organisms, such as the zebrafish. Researchers have identified a mammalian gene that normally acts as a molecular switch to block the regrowth of cochlear hair cells in adults. The Rb1 gene encodes the retinoblastoma protein, which is a tumor suppressor. Rb stops cells from dividing by encouraging their exit from the cell cycle. Not only do hair cells in a culture dish regenerate when the Rb1 gene is deleted, but