de Vetten N C, Ferl R J
Department of Genetics, Free University, Amsterdam, The Netherlands.
Plant J. 1995 Apr;7(4):589-601. doi: 10.1046/j.1365-313x.1995.7040589.x.
G-box cis-acting DNA sequence elements are present in the promoter region of a number of signal-inducible plant genes. In many cases this motif is essential for gene expression. Maize nuclear extracts contain a protein complex that binds specifically to the G-box sequence. Previously, a protein called GF14 was described that is physically associated with the G-box binding complex, but is not a DNA-binding factor in and of itself. This paper reports the isolation of a cDNA encoding a maize G-box binding factor (GBF). The deduced amino acid sequence indicates that maize GBF1 is a basic region-leucine zipper protein. GBF1 binds to the G-box element with specificity similar to that of the binding activity in nuclear extracts. Furthermore, maize GBF1 and the factor detected in nuclear extract are identical in their molecular weight and are immunologically related. GBF1 mRNA accumulates rapidly in hypoxically induced maize cells prior to the increase in Adh1 mRNA levels. Taken together with results that indicate that GBF1 binds to the hypoxia-responsive promoter of maize Adh1, these observations suggest that GBF1 may be one of the factors involved in the activation of Adh1.
G盒顺式作用DNA序列元件存在于许多信号诱导型植物基因的启动子区域。在许多情况下，这个基序对于基因表达至关重要。玉米核提取物含有一种与G盒序列特异性结合的蛋白质复合物。以前，曾描述过一种名为GF14的蛋白质，它与G盒结合复合物存在物理关联，但自身并非DNA结合因子。本文报道了一个编码玉米G盒结合因子（GBF）的cDNA的分离。推导的氨基酸序列表明，玉米GBF1是一种碱性区域-亮氨酸拉链蛋白。GBF1与G盒元件的结合特异性类似于核提取物中的结合活性。此外，玉米GBF1和在核提取物中检测到的因子分子量相同且存在免疫相关性。在缺氧诱导的玉米细胞中，GBF1 mRNA在Adh1 mRNA水平升高之前迅速积累。结合表明GBF1与玉米Adh1的缺氧应答启动子结合的结果，这些观察结果表明GBF1可能是参与Adh1激活的因子之一。
