Sp1 upregulates the proximal promoter activity of the mouse collagen α1(XI) gene (Col11a1) in chondrocytes.
Type XI collagen is a cartilage-specific extracellular matrix, and is important for collagen fibril formation and skeletal morphogenesis. We have previously reported that NF-Y regulated the proximal promoter activity of the mouse collagen α1(XI) gene (Col11a1) in chondrocytes (Hida et. al. In Vitro Cell. Dev. Biol. Anim. 2014). However, the mechanism of the Col11a1 gene regulation in chondrocytes has not been fully elucidated. In this study, we further characterized the proximal promoter activity of the mouse Col11a1 gene in chondrocytes. Cell transfection experiments with deletion and mutation constructs indicated that the downstream region of the NF-Y binding site (-116 to +1) is also necessary to regulate the proximal promoter activity of the mouse Col11a1 gene. This minimal promoter region has no TATA box and GC-rich sequence; we therefore examined whether the GC-rich sequence (-96 to -67) is necessary for the transcription regulation of the Col11a1 gene. Luciferase assays using a series of mutation constructs exhibited that the GC-rich sequence is a critical element of Col11a1 promoter activity in chondrocytes. Moreover, in silico analysis of this region suggested that one of the most effective candidates was transcription factor Sp1. Consistent with the prediction, overexpression of Sp1 significantly increased the promoter activity. Furthermore, knockdown of Sp1 expression by siRNA transfection suppressed the proximal promoter activity and the expression of endogenous transcript of the mouse Col11a1 gene. Taken together, these results indicate that the transcription factor Sp1 upregulates the proximal promoter activity of the mouse Col11a1 gene in chondrocytes.
Department of Matrix medicine, Faculty of medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.|Department of Oral and Maxillo-Facial Surgery, Faculty of medicine, Oita University, 1-1, Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
Keijirou
K
Watanabe
Department of Matrix medicine, Faculty of medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
Mariko
M
Hida
Department of Matrix medicine, Faculty of medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
Takako
T
Sasaki
Division of Radioisotope Research, Department of Research Support, Research Promotion Project, Faculty of medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
Hiroyuki
H
Yano
Department of Oral and Maxillo-Facial Surgery, Faculty of medicine, Oita University, 1-1, Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
Kenji
K
Kawano
Department of Matrix medicine, Faculty of medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
Hidekatsu
H
Yoshioka
Department of Matrix medicine, Faculty of medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan. matsuon@oita-u.ac.jp.
Noritaka
N
Matsuo
D000818:Animals; D001665:Binding Sites; D023081:CCAAT-Binding Factor / Q000235:genetics; D002356:Cartilage / Q000254:growth & development / Q000378:metabolism*; D019902:Chondrocytes / Q000378:metabolism*; D024161:Collagen Type XI / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D051379:Mice; D011401:Promoter Regions, Genetic; D016329:Sp1 Transcription Factor / Q000096:biosynthesis* / Q000235:genetics
D023081:CCAAT-Binding Factor; C497046:Col11a2 protein, mouse; D024161:Collagen Type XI; D004268:DNA-Binding Proteins; D016329:Sp1 Transcription Factor
Chondrocyte; Promoter; Sp1; Transcription; Type XI collagen