passages.id: split_6_test_42_passage
passages.type: progene_text
passages.text: A 0.89 - kb fragment consisting of 480 bp of the promoter , exon 1 , and part of intron 1 expressed luciferase activity in two M1 receptor - expressing cell lines ( CCL-107 and CCL - 147 ) , whereas a longer fragment ( 1.5 kb ) that extends into intron 2 demonstrated significantly increased luciferase activity .