粗糙脉孢菌前纤维蛋白Y86和R88位点突变抑制菌丝生长

微丝骨架在真菌的生长发育过程中发挥着重要的作用，而动力学特性是其实现功能的关键．前纤维蛋白（profilin）是肌动蛋白动态组装的主要调控因子，对其功能研究有助于阐明微丝骨架在真菌生长发育中的机制．本文以丝状真菌模式生物粗糙脉孢菌(Neurospora crassa)为材料，利用定点突变技术和同源重组技术，分别将前纤维蛋白上肌动蛋白结合位点86位酪氨酸（Y86）和88位精氨酸（R88）进行了单突变和双突变，获得了Y86R、R88E和Y86RR86E前纤维蛋白点突变株．进一步利用平板培养和竞争性生长管培养对点突变株的表型进行分析后发现，与野生型相比，3个前纤维蛋白点突变株的菌丝生长均明显减慢．这些结果表明，前纤维蛋白与肌动蛋白的相互作用对于N. crassa的生长和发育至关重要．

Profilin Mutations Y86R/R88E and Y86RR88E Inhibit Hyphal Growth in Neurospora crassa

The actin cytoskeleton is critical for hyphal growth in filamentous fungi for its dynamic nature. Profilin is a major regulator of actin assembly in eukaryotic cells. In the present study, Neurospora crassa was used as a experimental model to investigate the functions of profilin in hyphal growth. Conserved residues Y86 and R88 in the profilin of N. crassa at the actin binding site (essential for the interaction with actin) were mutated separately or in both via site directed mutagenesis and homologous recombination. The obtained mutants were introduced into N. crassa. Compared with the wild type, the profilin mutants attenuated the hyphal growth rate and led to abnormal morphologies. These observations suggested that profilin binding for actin was required for the hyphal growth.