Cloning and sequence analysis of the tyrosinase gene from a patient with tyrosinase-positive oculocutaneous albinism

Jun Matsunaga, Atsushi Takeda, Yasushi Tomita, Masahiro Hara, Shigeki Shibahara, Hachiro Tagami

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Tyrosinase is synthesized on membrane-bound ribosomes and transported into melanosomes through smooth endoplasmic reticulum and Golgi apparatus. Melanin polymers are produced only in melanosomes but never in smooth endoplasmic reticulum or Golgi apparatus, indicating that posttranslational modifications of tyrosinase are completed with melanosomes where tyrosinase becomes an active form. Based on a working hypothesis that tyrosinase-positive oculocutaneous albinism is a consequence of the structurally altered tyrosinase due to a point mutation in the gene of its gene coding for a glycosylation site or a membrane-binding site, which leads to the impairment in the posttranslational modification of tyrosinase and its catalytic activity, we have cloned the tyrosinase gene of one patient affected with tyrosinase-positive oculocutaneous albinism and determined its nucleotide sequence. Thus demonstrated all exons' nucleotide sequence of the patient's tyrosinase gene was found to be identical to that of the wild-type gene. The results indicate that the patient's tyrosinase itself is not altered. We therefore propose that the molecular basis for the development of tyrosinase-positive oculocutaneous albinism exists as a defect in other proteins required for the activation of tyrosinase or in other regions of the tyrosinase gene.

Original languageEnglish
Pages (from-to)181-185
Number of pages5
JournalJournal of dermatological science
Issue number3
Publication statusPublished - 1992 May
Externally publishedYes


  • Albinism
  • Melanin
  • Tyrosinase

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Dermatology


Dive into the research topics of 'Cloning and sequence analysis of the tyrosinase gene from a patient with tyrosinase-positive oculocutaneous albinism'. Together they form a unique fingerprint.

Cite this