Progress report on hair keratin research

Evidence is given for the progress in hair keratin research by bringing out four examples from the recent hair science literature. 1 Kon et al. [1] published a new method of solubilization and fractionation of the matrix and the microfibril proteins and found a significant decrease in the 'intact' microfibril keratin at the tip end of permed hair. 2 Contrary to the previous view of the existence of four major and one minor hair keratin pair, Langbein et al. [2, 3] showed that there are nine type I hair keratins and six type II hair keratins and drew up a two-dimensional catalogue of human hair keratins. 3 To collectively describe the extremely complex expression pattern of human type I and type II hair keratins in the hair follicle, Langbein et al. [2, 3] have summarized the corresponding RNA expression profiles of the various hair keratins schematically. 4 Contrary to the previous assignment of keratins exclusively to the microfibrils in the cortex, the mRNA expression studies of Langbein et al. [2, 3] implied that any hair cuticle cell leaving the living cell compartment contains four different hair keratins.