Gökirmak Tufan, Denison Fiona C, Laughner Beth J, Paul Anna-Lisa, Ferl Robert J
Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611, USA.
Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611, USA.
Plant Physiol Biochem. 2015 Dec;97:296-303. doi: 10.1016/j.plaphy.2015.10.022. Epub 2015 Oct 21.
14-3-3s are evolutionarily conserved eukaryotic regulatory proteins that are involved in diverse biological processes. The common mode of action for the 14-3-3 proteins is through the binding of phosphorylated target proteins. In many species, multiple 14-3-3 isoforms exist and these different isoforms can exhibit distinct ranges of target interactions. The dimerization of 14-3-3s is central to their function. 14-3-3 isoforms can form different combinations of homo- and heterodimers, which contribute to the broad functional diversity of the family. In this study, we showed that phosphomimetic mutation of a conserved serine residue in the dimerization interface of 14-3-3 isoforms, Ser-62, not only affects the ability of Arabidopsis 14-3-3ω to form homodimers, but alters the range of 14-3-3 family members with which it can form heterodimers. Furthermore, we demonstrated that the phosphorylation status of Ser-62 can regulate the binding of 14-3-3ω to target proteins, suggesting that Ser-62 might be a conserved key element to modulate target binding in both plants and animals.
14-3-3蛋白是进化上保守的真核生物调节蛋白，参与多种生物学过程。14-3-3蛋白的常见作用方式是通过与磷酸化的靶蛋白结合。在许多物种中，存在多种14-3-3亚型，这些不同的亚型可表现出不同范围的靶标相互作用。14-3-3蛋白的二聚化是其功能的核心。14-3-3亚型可形成同二聚体和异二聚体的不同组合，这导致了该家族广泛的功能多样性。在本研究中，我们表明，14-3-3亚型二聚化界面中一个保守的丝氨酸残基Ser-62的拟磷酸化突变，不仅影响拟南芥14-3-3ω形成同二聚体 的能力，而且改变了它能与之形成异二聚体的14-3-3家族成员范围。此外，我们证明Ser-62的磷酸化状态可调节14-3-3ω与靶蛋白的结合，这表明Ser-62可能是调节植物和动物中靶标结合的保守关键元件。
