Serum response factor-dependent regulation of the smooth muscle calponin gene. J Biol Chem 2000 Mar 31;275(13):9814-22
Date
03/29/2000Pubmed ID
10734136DOI
10.1074/jbc.275.13.9814Scopus ID
2-s2.0-0034737603 (requires institutional sign-in at Scopus site) 104 CitationsAbstract
Smooth muscle calponin is a multifunctional, thin filament-associated protein whose expression is restricted to smooth muscle cell lineages in developing and postnatal tissues. Although the physiology of smooth muscle calponin has been studied extensively, the cis-elements governing its restricted pattern of expression have yet to be identified. Here we report on smooth muscle-specific enhancer activity within the first intron of smooth muscle calponin. Sequence analysis revealed a proximal consensus intronic CArG box and two distal intronic CArG-like elements, each of which bound recombinant serum response factor (SRF) as well as immunoreactive SRF from smooth muscle nuclear extracts. Site-directed mutagenesis studies suggested that the consensus CArG box mediates much of the intronic enhancer activity; mutating all three CArG elements abolished the ability of SRF to confer enhancer activity on the smooth muscle calponin promoter. Cotransfecting a dominant-negative SRF construct attenuated smooth muscle-specific enhancer activity, and transducing smooth muscle cells with adenovirus harboring the dominant-negative SRF construct selectively reduced steady-state expression of endogenous smooth muscle calponin. These results demonstrate an important role for intronic CArG boxes and the SRF protein in the transcriptional control of smooth muscle calponin in vitro.
Author List
Miano JM, Carlson MJ, Spencer JA, Misra RPAuthor
Ravindra P. Misra PhD Associate Provost, Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBase Sequence
Calcium-Binding Proteins
Cells, Cultured
DNA
DNA-Binding Proteins
Enhancer Elements, Genetic
Gene Expression Regulation
Introns
Male
Microfilament Proteins
Molecular Sequence Data
Muscle, Smooth
Nuclear Proteins
Protein Binding
Rats
Rats, Sprague-Dawley
Serum Response Factor
