passages.id: split_5_test_1129_passage
passages.type: progene_text
passages.text: We now identify LDLR promoter region - 17 to - 1 as a sterol - independent regulatory element ( SIRE ) that is critically involved in OM - , transcription factor CCAAT / enhancer - binding protein ( C / EBP ) - , and second messenger cAMP - mediated activation of LDLR transcription .