Keratin 33A (KRT33A)

KRT33A is a member of the keratin gene family. It is one of the type I hair keratin genes which are clustered in a region of chromosome 17q12-q21 and have the same direction of transcription. As a type I hair keratin, it is an acidic protein which heterodimerizes with type II keratins to form hair and nails. There are two isoforms of this protein, encoded by two separate genes, KRTHA3A and KRTHA3B.

Rogers et al. (1998) reported that the deduced KRTHA3A protein has 405 amino acids and shares 93.3% amino acid sequence identity with KRTHA3B. By RT-PCR, Rogers et al. (1998) showed that KRTHA3A is expressed in the human hair follicle. See Langbein et al. (1999) for further details on the expression pattern of the KRTHA3A gene in the hair follicle.