A novel SREBP-1 splice variant: Tissue abundance and transactivation potency

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• 作者：Thomas Klaus Felder ; Kerstin Klein ; Wolfgang Patsch and Hannes Oberkofler
• 关键词：SREBP-1 ; Alternative splicing ; Transcriptional regulation
• 刊名：Biochimica et Biophysica Acta (BBA)/Gene Structure and Expression
• 出版年：2005
• 出版时间：2005
• 年：2005
• 卷：1731
• 期：1
• 页码：41-47
• 全文大小：269 K

文摘

Sterol regulatory element binding proteins (SREBPs) belong to the family of basic helix–loop–helix–leucine zipper transcription factors. The SREBP-1 gene encodes two different isoforms, SREBP-1a and -1c, that are expressed at varying levels in different tissues and cultured cells and exhibit common and distinct functions. We identified an additional SREBP-1 isoform, termed SREBP-1ac, and determined its mRNA abundance in different human tissues and cell lines. SREBP-1ac mRNA was detectable in all tissues studied, although at lower levels than the major SREBP-1a and -1c isoforms. Transcription of the novel SREBP isoform was not induced by insulin or cholesterol depletion. SREBP-1ac did not transactivate the human LDLR and UCP2 promoters but robustly attenuated the transactivation capacity of SREBP-1a, -1c and -2 in cotransfection experiments.