THE 5'-PLANKING REGION OF THE HUMAN SMOOTH-MUSCLE CELL CALPONIN GENE CONTAINS A CIS-ACTING DOMAIN FOR INTERACTION WITH A METHYLATED DNA-BINDING TRANSCRIPTION REPRESSOR

The human smooth muscle cell (SMC) calponin gene, which is composed of seven exons and six introns, spanning an approximately 11.2 kilobase (kb) genomic DNA, has been isolated and characterized by sequence anal ysis, As determined by primer extension mapping and rapid amplificatio n of mRNA transcripts, a major transcription start site of the calponi n gene is located at 101 base-pairs (bp) upstream of the ATG start cod on, A striking feature of the 5'-flanking, 5'-untranslated, and amino terminal protein coding regions is the presence of an Alu repetitive s equence and a stretch of DNA sequence identified using a methyl CpG-bi nding protein affinity column [Cross, S.H,, Charlton, J.A., Nan, X., a nd Bird, A.P. (1994) Nature Genet. 6, 236-244]. The results of this st udy provide a new insight into the molecular mechanism underlying regu lation of SMC-lineage specific gene expression.