α-Sarcoglycan striated muscle-specific protein is a member of the sarcoglycan-sarcospan complex. Positive and negative transcriptional regulation of sarcoglycan genes are important in sarcoglycan's intracellular localization and sarcolemmal stability. In the present work we assessed the function of NFI transcription factors in the regulation of α-sarcoglycan promoter through the C2C12 cell line differentiation. NFI factors act alternatively as activators and negative modulators of α-sarcoglycan promoter activity. In myoblasts NFI-A1.1 and NFI-B2 are activators, whereas NFI-C2 and NFI-X2 are negative regulators. In myotubes, all NFI members are activators, being NFI-C2 the less potent. We identified the α-sarcoglycan promoter NFI-C2 response element by testing progressive deletion constructs and point mutations in C2C12 cells over-expressing NFI-C2. Gel-shift and chromatin immunoprecipitation experiments demonstrated that NFI factors are indeed interacting in vitro and in vivo with the binding sequence. These results suggest a NFI role in C2C12 cell differentiation.
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2 Jul 2004|
Bibliographical noteFunding Information:
P. Delgado-Olguı́n is a Ph.D. student supported by the Consejo Nacional de Ciencia y Tecnologı́a (CONACyT) through the Grant 158524, by the Dirección General de Estudios de Posgrado, UNAM, and by the IMSS fellowship award. We gratefully acknowledge funding support from Association Française contre les Myopathies (Grant MNM 2000 Group 1). This work was partially supported by CONACyT (Grant 33863-N and 42653-Q), PAPIIT-DGAPA (IN203200 and IN209403), The Third World Academy of Sciences (TWAS, Grant 01-055RG/BIO/LA), and the Fundación Miguel Alemán to F.R.T. We thank Georgina Guerrero Avendaño for excellent technical assistance.
Copyright 2008 Elsevier B.V., All rights reserved.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology