Laboratory of Molecular Genetics, Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, 400 076, India.
Mol Biol Rep. 2022 Oct;49(10):9387-9396. doi: 10.1007/s11033-022-07792-5. Epub 2022 Jul 31.
Diploid cells of Saccharomyces cerevisiae undergo either pseudohyphal differentiation or sporulation in response to depletion of carbon and nitrogen sources. Distinct signaling pathways regulate filamentation and sporulation in response to nutrient limitation. How these pathways are coordinated for implementing distinct cell fate decisions in response to similar nutritional cues is an enigma. Although the role of trehalose pathway in sporulation has been extensively studied, it's possible role in pseudohyphal differentiation has been unexplored.
Briefly, tps1 and tps2 mutants were tested for their ability to form pseudohyphae independently as well as in the background of GPR1 and RAS2 mutations. Here, we demonstrate that disruption of TPS1 but not TPS2 inhibits pseudohyphae formation. Interestingly, deletion of GPR1 suppresses the above defect. Further genetic analysis revealed that TPS1 and TPS2 exert opposing effects in triggering filamentation.
We provide new insights into the role of an otherwise well-known pathway of trehalose biosynthesis in pseudohyphal differentiation. Based on additional data we propose that downstream signaling, mediated by cAMP may be modulated by nutrient mediated differential regulation of RAS2 by TPS1 and TPS2.
酿酒酵母的二倍体细胞在碳源和氮源耗尽时，会发生假菌丝分化或孢子形成。不同的信号通路调节丝状生长和孢子形成以响应营养限制。这些途径如何协调以响应类似的营养线索做出不同的细胞命运决定，这是一个谜。尽管海藻糖途径在孢子形成中的作用已被广泛研究，但它在假菌丝分化中的可能作用尚未被探索。
简要地说，tps1 和 tps2 突变体被测试其独立形成假菌丝的能力，以及在 GPR1 和 RAS2 突变的背景下。在这里，我们证明了 TPS1 的破坏而不是 TPS2 的破坏抑制了假菌丝的形成。有趣的是，GPR1 的缺失抑制了上述缺陷。进一步的遗传分析表明，TPS1 和 TPS2 在触发丝状生长方面具有相反的作用。
我们为海藻糖生物合成这一众所周知的途径在假菌丝分化中的作用提供了新的见解。基于其他数据，我们提出 cAMP 介导的下游信号可能受到 TPS1 和 TPS2 通过营养物质调节 RAS2 的差异调节的调制。
