Plant Actin-Depolymerizing Factors Possess Opposing Biochemical Properties Arising from Key Amino Acid Changes throughout Evolution. Issue 2 (25th January 2017)

• Record Type: Journal Article
• Authors: Nan, Qiong; Qian, Dong; Niu, Yue; He, Yongxing; Tong, Shaofei; Niu, Zhimin; Ma, Jianchao; Yang, Yang; An, Lizhe; Wan, Dongshi; Xiang, Yun
• Is Part Of: The Plant Cell. Volume 29:Issue 2(2017)
• Page Start: 395
• Page End: 408
• Publication Date: 2017-01-25
• DOI: 10.1105/tpc.16.00690
• Languages: English
• ISSNs: 1040-4651

Abstract

Abstract : Plant actin-depolymerizing factors were derived from a common ancestor but have acquired opposing biochemical properties due to N-terminal extensions and conserved amino acid changes during evolution. Abstract: Functional divergence in paralogs is an important genetic source of evolutionary innovation. Actin-depolymerizing factors (ADFs) are among the most important actin binding proteins and are involved in generating and remodeling actin cytoskeletal architecture via their conserved F-actin severing or depolymerizing activity. In plants, ADFs coevolved with actin, but their biochemical properties are diverse. Unfortunately, the biochemical function of most plant ADFs and the potential mechanisms of their functional divergence remain unclear. Here, in vitro biochemical analyses demonstrated that all 11 ADF genes in Arabidopsis thaliana exhibit opposing biochemical properties. Subclass III ADFs evolved F-actin bundling (B-type) function from conserved F-actin depolymerizing (D-type) function, and subclass I ADFs have enhanced D-type function. By tracking historical mutation sites on ancestral proteins, several fundamental amino acid residues affecting the biochemical functions of these proteins were identified in Arabidopsis and various plants, suggesting that the biochemical divergence of ADFs has been conserved during the evolution of angiosperm plants. Importantly, N-terminal extensions on subclass III ADFs that arose from intron-sliding events are indispensable for the alteration of D-type to B-type function. We conclude that the evolution of these N-terminal extensions and several conserved mutations produced the diverse biochemical functions of plant ADFs from a putative ancestor.