EXPRESSION, GENOMIC STRUCTURE AND HIGH-RESOLUTION MAPPING TO 19P13.2 OF THE HUMAN SMOOTH-MUSCLE CELL CALPONIN GENE

Smooth muscle cells (SMC) express a battery of cell-restricted differe ntiation genes, many of which are down-regulated during the course of vascular disease. Here, we present the mRNA expression, genomic struct ure and chromosomal mapping of the gene encoding human smooth muscle c ell calponin (SMCC). Human SMCC transcripts are restricted to tissues and cells of SMC origin and, in the latter case, appear to be uniquely controlled in two distinct human SMC lines of uterine and aortic orig in. Restriction mapping, Southern blot and PCR analysis of a 70-kb hum an bacterial artificial chromosome (BAG) revealed a genomic structure (seven exons spanning > 11 kb) very similar to that reported for the m ouse SMCC gene. Using a variety of human-rodent somatic cell hybrid an d radiation hybrid mapping panels, the human SMCC gene was mapped to a genomic interval of less than 1.32 Mb in 19p13.2. These results provi de new information concerning the regulation of SMCC gene expression a nd demonstrate the utility of two human SMC lines for the further char acterization of this gene's expression control. The identification of a BAC harboring the entire human SMCC locus represents an important re agent for future analysis of SMCC regulatory sequences. Finally, the l ocalization of SMCC to a defined genomic interval will facilitate an a nalysis of its potential as a candidate gene for disease phenotypes ma pping to 19p13.2. (C) 1997 Elsevier Science B.V.