Pearce G, Moura D S, Stratmann J, Ryan C A
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA.
Proc Natl Acad Sci U S A. 2001 Oct 23;98(22):12843-7. doi: 10.1073/pnas.201416998. Epub 2001 Oct 2.
A 5-kDa polypeptide was isolated from tobacco leaves that induced a rapid alkalinization of the culture medium of tobacco suspension-cultured cells and a concomitant activation of an intracellular mitogen-activated protein kinase. An N-terminal sequence was obtained, and a cDNA coding for the 49-aa polypeptide was isolated from a tobacco cDNA library. The cDNA encoded a preproprotein of 115 amino acids that contained the polypeptide at its C terminus. A search among known expressed sequence tags revealed that genes encoding Rapid ALkalinization Factor (RALF) preproproteins were present in various tissues and organs from 16 species of plants representing 9 families. A tomato homolog of the polypeptide was synthesized and, when supplied to germinating tomato and Arabidopsis seeds, it caused an arrest of root growth and development. Although its specific role in growth has not been established, the polypeptide joins the ranks of the increasing number of polypeptide hormones that are known to regulate plant stress, growth, and development.
从烟草叶片中分离出一种5千道尔顿的多肽，它能使烟草悬浮培养细胞的培养基迅速碱化，并同时激活细胞内的丝裂原活化蛋白激酶。获得了其N端序列，并从烟草cDNA文库中分离出编码该49个氨基酸多肽的cDNA。该cDNA编码一个115个氨基酸的前体蛋白，其C端含有该多肽。在已知的表达序列标签中进行搜索发现，编码快速碱化因子（RALF）前体蛋白的基因存在于代表9个科的16种植物的各种组织和器官中。合成了该多肽的番茄同源物，当将其提供给萌发的番茄和拟南芥种子时，它会导致根的生长和发育停滞。尽管其在生长中的具体作用尚未确定，但该多肽加入了已知可调节植物应激、生长和发育的越来越多的多肽激素行列。
