Further, CNN showed a weak but significant direct inhibitory effect on the enzymatic activity of tyrosinase, suggesting one possible mechanism of hypopigmentation.
Tyrosinase catalyzes the key step of melanogenesis, dysfunction of tyrosinase leads to reduce melanin production which results in severe clinical and aesthetical problems of hypopigmentation.
Taken together, CFAB is a unique reagent that primarily accelerates tyrosinase decrease by a mechanism that differs from those considered for other hypopigmentation reagents currently reported.
The substantial reduction of SLC45A2 protein in the patient's melanocytes caused the mislocalization of tyrosinase from melanosomes to the plasma membrane and also led to the incorporation of tyrosinase into exosomes and secretion into the culture medium, explaining the hypopigmentation in OCA-4.
Yellow oculocutaneous albinism (OCA) that is caused by tyrosinase gene mutations shows two characteristics: extreme hypopigmentation at birth and the eventual development of yellow or blond hair.
Tyrosinase inhibition due to interaction of homocyst(e)ine with copper: the mechanism for reversible hypopigmentation in homocystinuria due to cystathionine beta-synthase deficiency.
A novel type I OCA phenotype in which hypopigmentation is related to local body temperature is associated with a missense substitution in tyrosinase, codon 422 CGG (Arg)----CAG (Gln).
Hairbulb tyrosinase activity and glutathione content, as well as urine cysteinyldopa excretion, were low in PWS individuals with and without hypopigmentation and did not separate these two groups.