Das Satarupa, Parker Joshua M, Guven Can, Wang Weiye, Kriebel Paul W, Losert Wolfgang, Larson Daniel R, Parent Carole A
Laboratory of Cellular and Molecular Biology, Center for Cancer Research, 37 Convent Drive, Bldg.37/Rm2066, NCI, NIH, Bethesda, MD, 20892-4256, USA.
Institute for Physical Science and Technology, Department of Physics, University of Maryland, College Park, MD, 20742, USA.
BMC Cell Biol. 2017 May 25;18(1):23. doi: 10.1186/s12860-017-0139-7.
In Dictyostelium discoideum, vesicular transport of the adenylyl cyclase A (ACA) to the posterior of polarized cells is essential to relay exogenous 3',5'-cyclic adenosine monophosphate (cAMP) signals during chemotaxis and for the collective migration of cells in head-to-tail arrangements called streams.
Using fluorescence in situ hybridization (FISH), we discovered that the ACA mRNA is asymmetrically distributed at the posterior of polarized cells. Using both standard estimators and Monte Carlo simulation methods, we found that the ACA mRNA enrichment depends on the position of the cell within a stream, with the posterior localization of ACA mRNA being strongest for cells at the end of a stream. By monitoring the recovery of ACA-YFP after cycloheximide (CHX) treatment, we observed that ACA mRNA and newly synthesized ACA-YFP first emerge as fluorescent punctae that later accumulate to the posterior of cells. We also found that the ACA mRNA localization requires 3' ACA cis-acting elements.
Together, our findings suggest that the asymmetric distribution of ACA mRNA allows the local translation and accumulation of ACA protein at the posterior of cells. These data represent a novel functional role for localized translation in the relay of chemotactic signal during chemotaxis.
在盘基网柄菌中，腺苷酸环化酶A（ACA）向极化细胞后部的囊泡运输对于在趋化作用期间传递外源性3',5'-环磷酸腺苷（cAMP）信号以及细胞以头尾排列方式形成称为流的集体迁移至关重要。
使用荧光原位杂交（FISH），我们发现ACA mRNA在极化细胞的后部不对称分布。使用标准估计器和蒙特卡罗模拟方法，我们发现ACA mRNA的富集取决于细胞在流中的位置，对于流末端的细胞，ACA mRNA的后部定位最强。通过监测环己酰亚胺（CHX）处理后ACA-YFP的恢复情况，我们观察到ACA mRNA和新合成的ACA-YFP首先以荧光斑点的形式出现，随后积累到细胞的后部。我们还发现ACA mRNA定位需要3' ACA顺式作用元件。
总之，我们的研究结果表明，ACA mRNA的不对称分布允许ACA蛋白在细胞后部进行局部翻译和积累。这些数据代表了局部翻译在趋化作用期间趋化信号传递中的一种新功能作用。
