Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Cell Rep. 2021 Mar 2;34(9):108799. doi: 10.1016/j.celrep.2021.108799.
The Tre1 G-protein coupled receptor (GPCR) was discovered to be required for Drosophila germ cell (GC) coalescence almost two decades ago, yet the molecular events both upstream and downstream of Tre1 activation remain poorly understood. To gain insight into these events, we describe a bona fide null allele and both untagged and tagged versions of Tre1. We find that the primary defect with complete Tre1 loss is the failure of GCs to properly navigate, with GC mis-migration occurring from early stages. We find that Tre1 localizes with F-actin at the migration front, along with PI(4,5)P; dPIP5K, an enzyme that generates PI(4,5)P; and dWIP, a protein that binds activated Wiskott-Aldrich syndrome protein (WASP), which stimulates F-actin polymerization. We show that Tre1 is required for polarized accumulation of F-actin, PI(4,5)P, and dPIP5K. Smoothened also localizes with F-actin at the migration front, and Hh, through Smo, increases levels of Tre1 at the plasma membrane and Tre1's association with dPIP5K.
Tre1 G 蛋白偶联受体 (GPCR) 大约在二十年前被发现是果蝇生殖细胞 (GC) 融合所必需的，但 Tre1 激活的上下游分子事件仍知之甚少。为了深入了解这些事件，我们描述了一个真正的无效等位基因和未标记和标记的 Tre1 版本。我们发现，完全缺失 Tre1 的主要缺陷是 GC 无法正常导航，GC 错位发生在早期阶段。我们发现 Tre1 与迁移前沿的 F-肌动蛋白以及 PI(4,5)P 一起定位；dPIP5K，一种生成 PI(4,5)P 的酶；和 dWIP，一种与激活的 Wiskott-Aldrich 综合征蛋白 (WASP) 结合的蛋白质，该蛋白刺激 F-肌动蛋白聚合。我们表明 Tre1 是极化积累 F-肌动蛋白、PI(4,5)P 和 dPIP5K 所必需的。Smo 也与迁移前沿的 F-肌动蛋白一起定位，Hh 通过 Smo 增加质膜上 Tre1 的水平及其与 dPIP5K 的关联。
