Czarnecka-Verner E, Yuan C X, Fox P C, Gurley W B
Department of Microbiology and Cell Science, University of Florida, Gainesville 32611-0700, USA.
Plant Mol Biol. 1995 Oct;29(1):37-51. doi: 10.1007/BF00019117.
Thermal stress in soybean seedlings causes the activation of pre-existing heat shock transcription factor proteins (HSFs). Activation results in the induction of DNA binding activity which leads to the transcription of heat shock genes. From a soybean cDNA library we have isolated cDNA clones corresponding to six HSF genes. Two HSF genes are expressed constitutively at the transcriptional level, and the remaining four are heat-inducible. Two of the heat inducible genes are also responsive to cadmium stress. Comparative analysis of HSF sequences indicated higher conservation of the DNA binding domain among plant HSFs than those from yeast or other higher eukaryotes. The putative plant HSF oligomerization domain contains hydrophobic heptapeptide repeats characteristic of coiled coils and seems to exist in two structural variants. The carboxy-terminal domains are reduced in size and the C-terminal heptad repeat is degenerate.
大豆幼苗中的热应激会导致预先存在的热休克转录因子蛋白（HSFs）被激活。激活会导致DNA结合活性的诱导，进而引发热休克基因的转录。我们从大豆cDNA文库中分离出了对应于六个HSF基因的cDNA克隆。其中两个HSF基因在转录水平上组成性表达，其余四个是热诱导型的。两个热诱导基因也对镉胁迫有反应。HSF序列的比较分析表明，与酵母或其他高等真核生物相比，植物HSFs中DNA结合结构域的保守性更高。推测的植物HSF寡聚化结构域包含卷曲螺旋特有的疏水七肽重复序列，似乎存在两种结构变体。羧基末端结构域的大小减小，C末端七肽重复序列退化。
