VASCULAR CELL-ADHESION MOLECULE-1 - CONTRASTING TRANSCRIPTIONAL CONTROL MECHANISMS IN MUSCLE AND ENDOTHELIUM
VASCULAR CELL-ADHESION MOLECULE-1 - CONTRASTING TRANSCRIPTIONAL CONTROL MECHANISMS IN MUSCLE AND ENDOTHELIUM
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DOI：
10.1073/pnas.90.9.3943
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发表时间：
1993-05-01
影响因子：
11.1
通讯作者：
DEAN, DC
中科院分区：
文献类型：
--
作者：
IADEMARCO, MF;MCQUILLAN, JJ;DEAN, DC
Interaction between vascular cell adhesion molecule 1 (VCAM-1), which appears on the surface of endothelial cells in response to inflammation, and its integrin counter receptor, alpha4beta1, on immune cells is responsible for targeting these immune cells to cytokine-stimulated endothelium. In addition to its role in the immune system, VCAM-1 is also expressed in a developmentally specific pattern on differentiating skeletal muscle, where it mediates cell-cell interactions important for myogenesis through interaction with alpha4beta1. In contrast to endothelium, there is high basal expression of VCAM-1 in skeletal muscle cells and the expression is not cytokine-responsive. Here, we examine the molecular basis for these contrasting patterns of expression in muscle and endothelium, using VCAM-1 promoter constructs in a series of transfection assays. In endothelial cells, octamer binding sites act as silencers that prevent VCAM-1 expression in unstimulated cells. Tumor necrosis factor alpha overcomes the negative effects of these octamers and activates the promoter through two adjacent NF-kappaB binding sites. In muscle cells, a position-specific enhancer located between bp -21 and -5 overrides the effect of other promoter elements, resulting in constitutive VCAM-1 expression. A nuclear protein binds the position-specific enhancer in muscle but not endothelial cells; thus the pattern of expression of this protein could control enhancer activity.
