 Then, Phospho-AI-2 binds the transcriptional repressor protein, LsrR, which subsequently is released from the promoter/operator region of the lsr operon – and transcription of the "lsr" genes is initiated.AI-2 signalling is also regulated by glucose and cAMP/CRP via the "lsr" operon.In the presence of glucose, low levels of cAMP/CRP result in almost no "lsr" operon ("lsrABCDFG") expression.