Keratin 73 (KRT73)

KRT73 has a calculated molecular mass of 59 kD. K6IRS3 shares a highly conserved rod domain and flanking non-alpha-helical H1 and H2 subdomains with K6IRS1, K6IRS2, and K6IRS4. The head and tail domains are less related. Western blot analysis detected a single K6IRS3 band in root sheath extracts, but not in foot sole extracts. In situ hybridization of plucked beard hair follicles and human scalp showed that K6IRS2 and K6IRS3 were exclusively expressed in the cuticle of the inner root sheath, but they showed different onsets of expression. K6IRS3 was expressed between the lowermost bulb region of the cuticle and the region where Henle cells undergo abrupt terminal differentiation. K6IRS3 protein was detected up to the uppermost cortex region where cuticle cells terminally differentiate.