Abstract：
Protein complex Arp2/3 has a conserved role in the nucleation of branched actin filaments. It is constituted of seven subunits, including actin-like subunits ARP2 and ARP3 plus five other subunits called Arp2/3 Complex Component 1 to 5, which are not related to actin. Knock-out plant mutants lacking individual plant ARP2/3 subunits have a typical phenotype of distorted trichomes, altered pavement cells shape and defects in cell adhesion. While knock-out mutant Arabidopsis plants for most ARP2/3 subunits have been characterized before, Arabidopsis plant mutants missing ARPC1 and ARPC3 subunits have not yet been described. Using CRISPR/Cas9, we generated knock-out mutants lacking ARPC1 and ARPC3 subunits. We confirmed that the loss of ARPC1 subunits results in the typical ARP2/3 mutant phenotype. However, the mutants lacking ARPC3 subunits resulted in plants with surprisingly different phenotypes. Our results suggest that plant ARP2/3 complex function in trichome shaping does not require ARPC3 subunit, while the fully assembled complex is necessary for the establishment of correct cell adhesion in the epidermis.
摘要：
蛋白质复合物Arp2/3在支链肌动蛋白丝的成核中具有保守作用。它由七个子单元组成，包括肌动蛋白样亚基ARP2和ARP3以及五个与肌动蛋白无关的称为Arp2/3复合物成分1至5的其他亚基。缺乏单个植物ARP2/3亚基的敲除植物突变体具有典型的扭曲毛状体表型，改变路面细胞形状和细胞粘附缺陷。虽然大多数ARP2/3亚基的敲除突变拟南芥植物之前已经被表征，尚未描述缺失ARPC1和ARPC3亚基的拟南芥植物突变体。使用CRISPR/Cas9,我们产生缺乏ARPC1和ARPC3亚基的敲除突变体。我们证实ARPC1亚基的缺失导致典型的ARP2/3突变表型。然而,缺乏ARPC3亚基的突变体导致植物具有惊人的不同表型。我们的结果表明，植物ARP2/3复合功能在毛状体成形中不需要ARPC3亚基，而完全组装的复合物对于在表皮中建立正确的细胞粘附是必要的。
