Transcriptional activation of the mouse HSP47 gene in mouse osteoblast MC3T3-E1 cells by TGF-beta 1.
HSP47 is a 47-kDa collagen-binding heat shock protein, the expression of which is always correlated with that of collagens in various cell lines. We examined the effects of TGF-beta 1, which is reported to induce the collagen genes, on the expression of HSP47 in mouse osteoblast MC3T3-E1 cells. Treatment of the cells with 5 ng/ml TGF-beta 1 for 24 h increased the level of HSP47 mRNA three-fold. Dose-dependent induction by TGF-beta 1 was observed for both HSP47 mRNA and collagen alpha 1 (I) mRNA, and actinomycin D inhibited this increase of HSP47 mRNA. To elucidate the TGF-beta 1 responsive element(s) in the mouse HSP47 gene, we generated a series of 5'-deletion promoters fused to luciferase reporter constructs. Transient transfection assays showed that TGF-beta 1 induced 4-6 fold the promoter activity of a region approximately -5.5 kbp upstream of the HSP47 gene. Two upstream regions, -3.9 to -2.7 kbp and -280 to -50 bp were shown to be involved in the activation in response to TGF-beta 1 treatment.
Yamamura
I
I
Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Kyoto University, Japan.
Hirata
H
H
Hosokawa
N
N
Nagata
K
K
D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D050958:HSP47 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D010006:Osteoblasts / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D050958:HSP47 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C494660:SERPINH1 protein, human; C494661:Serpinh1 protein, mouse; D016212:Transforming Growth Factor beta; D003609:Dactinomycin; D003094:Collagen