The STRIPAK signaling complex regulates dephosphorylation of GUL1, an RNA-binding protein that shuttles on endosomes

STRIPAK is a highly conserved eukaryotic signalling complex controlling a wide range of developmental processes in microorganisms as well as humans. This study uses iTRAQ-based proteomic and phosphoproteomic analyses to expand the identification of differentially phosphorylated proteins, comparing the wildtype proteome of the model fungus S. macorspora to those from three STRIPAK single- and double deletion mutants. Among the differentially phosphorylated proteins, we detected Gul1, a homolog of GUL-1 from N. crassa and SSD1 from yeast. In this study, we further provide a functional analysis of Gul1, showing it controls sexual development and hyphal morphology in a phosphorylation dependent manner.

STRIPAK复合体是一类高度保守的真核信号复合物，可调控微生物与人类体内的多种发育进程。本研究采用基于iTRAQ的蛋白质组学及磷酸化蛋白质组学分析方法，拓展了差异磷酸化蛋白的鉴定范围，将模式真菌S. macorspora的野生型蛋白质组与3株STRIPAK单缺失及双缺失突变体的蛋白质组进行对比。在检测到的差异磷酸化蛋白中，我们发现了Gul1——其为粗糙脉孢霉（N. crassa）GUL-1与酵母SSD1的同源蛋白。本研究进一步对Gul1开展了功能分析，结果表明其通过磷酸依赖的方式调控有性发育与菌丝形态。