A human inborn genetic disease, type I phenylketonuria [13] (PKU) is caused by a mutation in the gene encoding the enzyme phenylalanine dehydrogenase necessary to convert L-phenylalanine (L-Phe) to L-tyrosine, (L-Tyr). The accumulated L-Phe is metabolized by enforced side reaction to phenylpyruvate, phenylacetate, and phenyl-L-lactate excreted with urine, Fig. 1. The excess of phenylalanine hin...

BACKGROUND Tyrosinase (TYR) catalyzes the rate-limiting, first step in melanin production and its gene (TYR) is mutated in many cases of oculocutaneous albinism (OCA1), an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the ab...

Functions of viral proteins can be regulated through phosphorylation by serine/threonine kinases in plants, but little is known about the involvement of tyrosine kinases in plant virus infection. In this study, TGBp3, one of the three movement proteins encoded by a triple gene block (TGB) of Potato mop-top virus (PMTV), was detected for the first time in PMTV-infected plants and found to be tyr...

Reactivation of androgen receptor (AR) may drive recurrent prostate cancer in castrate patients. Ack1 tyrosine kinase is overexpressed in prostate cancer and promotes castrate resistant xenograft tumor growth and enhances androgen target gene expression and AR recruitment to enhancers. Ack1 phosphorylates AR at Tyr-267 and possibly Tyr-363, both in the N-terminal transactivation domain. In this...

TAL Effector Nucleases (TALENs) are versatile tools for targeted gene editing in various species. However, their efficiency is still insufficient, especially in mammalian embryos. Here, we showed that combined expression of Exonuclease 1 (Exo1) with engineered site-specific TALENs provided highly efficient disruption of the endogenous gene in rat fibroblast cells. A similar increased efficiency...

Mutations of the critical and rate-limiting melanogenic enzyme tyrosinase (Tyr) result in hypopigmentation of the hair, skin and eyes. Two other related enzymes, Tyrp1 and Dct, catalyze distinct post-Tyr reactions in melanin biosynthesis. Tyr, Tyrp1 and Dct have been proposed to interact with and stabilize each other in multi-enzyme complexes, and in vitro, Tyr activity is more stable in the pr...

We have shown previously that axonal microtubules (MTs) are composite, consisting of two distinct domains that differ in their content of tyrosinated alpha-tubulin (tyr-tub). One domain is poor in tyr-tub and is situated at the minus end of the MT. The other domain is rich in tyr-tub and extends from the plus end of the tyr-tub-poor domain to the end of the MT. We have proposed that the spatial...

Three cosmetically important skin lightening agents, hydroquinone (HQ), kojic acid (KA), and niacinamide (NA), consume the bulk of successful skin lightening ingredients in cosmetic applications. However, the mechanisms by which these ingredients work are still unclear. In this study, melanocytes and keratinocytes were treated with high, nontoxic doses of HQ, KA, and NA and the cells were exami...