THE MURINE GENE ENCODING SECRETED PHOSPHOPROTEIN-1 (OSTEOPONTIN) - PROMOTER STRUCTURE, ACTIVITY, AND INDUCTION INVIVO BY ESTROGEN AND PROGESTERONE

被引:164
作者
CRAIG, AM
DENHARDT, DT
机构
[1] UNIV WESTERN ONTARIO,CANC RES LAB,LONDON N6A 5B7,ONTARIO,CANADA
[2] UNIV WESTERN ONTARIO,DEPT BIOCHEM,LONDON N6A 5B7,ONTARIO,CANADA
基金
英国医学研究理事会;
关键词
PROMOTER ANALYSIS; GENE STRUCTURE; BONE SIALOPROTEIN; TRANSFORMATION-ASSOCIATED PHOSPHOPROTEIN; EARLY LYMPHOCYTE-T ACTIVATION-1; TUMOR PROMOTER INDUCTION;
D O I
10.1016/0378-1119(91)90362-F
中图分类号
Q3 [遗传学];
学科分类号
071007 ; 090102 ;
摘要
Secreted phosphoprotein 1 (Spp-1) is a 41.5-kDa bone sialprotein presumed to be important in the development and functioning of a number of mammalian organs and possibly also in the progression of malignancies. We report here the isolation of a phage lambda genomic clone of the murine Spp-1 gene containing the promoter and first six exons (4.6 kb of the 5.7-kb gene). We have found another exon located 5' to the 'exon 1' reported by Miyazaki et al. [J. Biol. Chem. 265 (1990) 14432-14438]. The DNA upstream from this 5' exon functions as a promoter in epidermal fibroblast and osteoblast-like cells, as demonstrated by transient transfection assays, S1 mapping of the transcription start point, and sequence analysis revealing TATA-like (TTTAAA) and CAAT (its inverse complement) boxes. A small region of the promoter (nt -253 to +79) was able to direct high-level expression of a fused cat reporter gene in JB6 mouse epidermal cells. The transient transfection assays indicated the presence of a positive transcription element between nt -543 and -253 and a negative transcription element between nt -777 and -543. Addition of the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), resulted in a 1.5-3-fold induction of transcription, depending on the promoter construct and the TPA concentration. The Spp-1 mRNA was localized in several tissues, consistent with previous reports, and to novel sites in ovary, and in the skin and ventral fatty tissue of pregnant and lactating mice. The induction of Spp-1 mRNA was partially mimicked by painting beta-estradiol or progesterone on the skin of nonpregnant females.
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页码:163 / 171
页数:9
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