摘要:

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 specifi

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1992.tb00453.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Complementary DNA clones coding for chicken tyrosinase were isolated from retinal pigmented epithelium of chicken embryo. Sequence analysis shows that one of the cDNA clones consisting of 1,997 nucleotides has an open reading frame coding for 529 amino acids. The deduced protein has nine N‐glycosylation sites and a transmembrane region. A sequence comparison of the deduced chicken tyrosinase with the mouse and human homologues revealed that amino acid sequences are conserved for the entire polypeptides. Seventy‐two percent and 73% of amino acids in the chicken sequence are identical to that of the mouse and human tyrosinases, respectively. Histidines neighboring the postulated copper‐binding sites and the cysteines are well conserved. RNA blotting analysis showed that a major transcript of 2.5 kb is detected in retinal pigmented epithelium of a 9‐day‐old chick

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1992.tb00454.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1992.tb00455.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1992.tb00456.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY