Kuwayama Hidekazu, Kubohara Yuzuru
Faculty of Life and Environmental Sciences, University of Tsukuba, Japan.
Department of Health Science, Graduate School of Health and Sports Science, Juntendo University, Inzai, Japan.
FEBS Lett. 2016 Mar;590(6):760-8. doi: 10.1002/1873-3468.12111. Epub 2016 Mar 4.
Differentiation-inducing factor 1(DIF-1) and DIF-2 are signaling molecules that control chemotaxis in Dictyostelium discoideum. Whereas DIF-1 suppresses chemotaxis in shallow cAMP gradients, DIF-2 enhances chemotaxis under the same conditions via a phosphodiesterase, response regulator A (RegA), which is a part of the DhkC-RdeA-RegA two-component signaling system. In this study, to investigate the mechanism of the chemotaxis regulation by DIF-2, we examined the effects of DIF-2 (and DIF-1) on chemotaxis in rdeA(-) and dhkC(-) mutant strains. In the parental wild-type strains, chemotactic cell movement was suppressed with DIF-1 and enhanced with DIF-2 in shallow cAMP gradients. In contrast, in both rdeA(-) and dhkC(-) strains, chemotaxis was suppressed with DIF-1 but unaffected by DIF-2. The results suggest that DIF-2 modulates chemotaxis via the DhkC-RdeA-RegA signaling system.
分化诱导因子1（DIF-1）和DIF-2是控制盘基网柄菌趋化性的信号分子。在浅浓度的环磷酸腺苷（cAMP）梯度中，DIF-1会抑制趋化性，而DIF-2则通过磷酸二酯酶、应答调节因子A（RegA）在相同条件下增强趋化性，RegA是DhkC-RdeA-RegA双组分信号系统的一部分。在本研究中，为了探究DIF-2对趋化性的调控机制，我们检测了DIF-2（和DIF-1）对rdeA（-）和dhkC（-）突变株趋化性的影响。在亲代野生型菌株中，在浅浓度的cAMP梯度中，趋化性细胞运动受到DIF-1的抑制，并受到DIF-2的增强。相反，在rdeA（-）和dhkC（-）菌株中，趋化性受到DIF-1的抑制，但不受DIF-2的影响。结果表明，DIF-2通过DhkC-RdeA-RegA信号系统调节趋化性。
