EXON-SPECIFIC NORTHERN ANALYSIS AND RAPID AMPLIFICATION OF CDNA ENDS (RACE) REVEAL THAT THE PROXIMAL PROMOTER-II (PII) IS RESPONSIBLE FOR AROMATASE CYTOCHROME-P-450 (CYP19) EXPRESSION IN HUMAN OVARY

[摘要] Estrogens are synthesized from C-19 steroids by a unique form of cytochrome P-450, aromatase cytochrome P-(450) (P-450(AROM); the product of the CYP19 gene). We have shown that tissue-specific expression of human P-450(AROM) is determined, in part, by the use of alternative promoters. Previous methods of analysis for determining the specific 5'-termini of the different transcripts included SI nuclease protection, primer extension, and Northern analysis. In the present study we have used the RACE procedure (rapid amplification of cDNA ends) to amplify and clone the 5' termini of P-450(AROM) transcripts expressed in human corpus luteum (CL). Sequencing of the resulting clones supports the results of the previously performed studies. Specifically, the proximal promoter, PII, is the predominant promoter utilized in CL, such that the start of transcription occurs 26 bp downstream of the putative TATA sequence. A minority of the clones possess an alternative 5'-end, namely I.3. Exon-specific Northern analysis confirms that the majority of the P-450(AROM) transcripts in CL tissue contain sequence specific for promoter II. Similarly, exon-specific Northern analysis indicates that transcripts in human follicles, as well as granulosa cells in culture, contain primarily sequence specific for promoter II.

[发布日期] 1993-11-01

[关键词] P-450(AROM);CYP19;NORTHERN BLOT;OVARY, HUMAN