A cis‐Acting Element Involved in Mouse Tyrosinase Gene Expression and Partial Purification of its Binding Protein

Academic Article

Abstract

  • The tyrosinase gene is specifically expressed in melanocytes. Understanding the molecular basis of tissue‐specific expression of the tyrosinase gene will greatly explain the mechanisms controlling pigmentation. We report a nucleotide sequence, TGATGTATTC, located ‐236 base pairs upstream of the transcription start site, that enhances tyrosinase gene expression in mouse melanoma cells. The sequence is referred to as the tyrosinase element‐1 (TE‐1). TE‐1 was protected from DNase I cleavage by pigment cell nuclear extracts but was not protected by non‐pigment cell nuclear extract. Partial purification of TE‐1 binding protein (TEBP‐1) was performed from the B16 mouse melanoma cell nuclear extract using biotin‐cellulose affinity chromatography. The affinity‐purified fraction exhibited binding to the DNA fragment containing TE‐1, and to a synthetic oligomer representing TE‐1. UV‐cross‐linking indicated that the size of TEBP‐1 is approximately 49 kD. TE‐1 also directed enhanced CAT activity in the B16 melanoma cells but not in non‐pigment cells. These data indicate that TE‐1 may be an enhancer element that is responsible for pigment cell specific expression of the tyrosinase gene. Copyright © 1992, Wiley Blackwell. All rights reserved
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    Digital Object Identifier (doi)

    Author List

  • PONNAZHAGAN S; KWON BS
  • Start Page

  • 155
  • End Page

  • 161
  • Volume

  • 5
  • Issue

  • 4