Nucleosome organization and targeting of SWI/SNF chromatin-remodeling complexes: contributions of the DNA sequence.
Chromatin organization within the nuclear compartment is a fundamental mechanism to regulate the expression of eukaryotic genes. During the last decade, a number of nuclear protein complexes with the ability to remodel chromatin and regulate gene transcription have been reported. Among these complexes is the SWI/SNF family, which alters chromatin structure in an ATP-dependent manner. A considerable effort has been made to understand the molecular mechanisms by which SWI/SNF catalyzes nucleosome remodeling. However, limited attention has been dedicated to studying the role of the DNA sequence in this remodeling process. Therefore, in this minireview, we discuss the contribution of nucleosome positioning and nucleosome excluding sequences to the targeting and activity of SWI/SNF complexes. This discussion includes results from our group using the rat osteocalcin gene promoter as a model. Based on these results, we postulate a model for chromatin remodeling and transcriptional activation of this gene in osteoblastic cells.
Montecino
Martin
M
Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile. mmonteci@udec.cl
Stein
Janet L
JL
Stein
Gary S
GS
Lian
Jane B
JB
van Wijnen
Andre J
AJ
Cruzat
Fernando
F
Gutiérrez
Soraya
S
Olate
Juan
J
Marcellini
Sylvain
S
Gutiérrez
José L
JL
D000818:Animals; D001483:Base Sequence; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D008957:Models, Genetic; D009707:Nucleosomes / Q000378:metabolism / Q000648:ultrastructure; D015675:Osteocalcin / Q000235:genetics; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D002868:Chromosomal Proteins, Non-Histone; D009707:Nucleosomes; C445179:SWI-SNF-B chromatin-remodeling complex; D014157:Transcription Factors; D015675:Osteocalcin; D004247:DNA