J Integr Plant Biol. ›› 2013, Vol. 55 ›› Issue (3): 250-261.DOI: 10.1111/jipb.12015

Special Issue: Cell Biology and Functions

• Cell and Developmental Biology • Previous Articles     Next Articles

Arabidopsis AtADF1 is Functionally Affected by Mutations on Actin Binding Sites

Chun-Hai Dong*, Wei-Ping Tang and Jia-Yao Liu   

  1. College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China
  • Received:2012-09-13 Accepted:2012-11-19 Published:2013-01-09
  • About author:*Corresponding author Tel/Fax: +86 532 8608 0640; E-mail: chunhai79@yahoo.com

Abstract:

The plant actin depolymerizing factor (ADF) binds to both monomeric and filamentous actin, and is directly involved in the depolymerization of actin filaments. To better understand the actin binding sites of the Arabidopsis thaliana L. AtADF1, we generated mutants of AtADF1 and investigated their functions in vitro and in vivo. Analysis of mutants harboring amino acid substitutions revealed that charged residues (Arg98 and Lys100) located at the α-helix 3 and forming an actin binding site together with the N-terminus are essential for both G- and F-actin binding. The basic residues on the β-strand 5 (K82/A) and the α-helix 4 (R135/A, R137/A) form another actin binding site that is important for F-actin binding. Using transient expression of CFP-tagged AtADF1 mutant proteins in onion (Allium cepa) peel epidermal cells and transgenic Arabidopsis thaliana L. plants overexpressing these mutants, we analyzed how these mutant proteins regulate actin organization and affect seedling growth. Our results show that the ADF mutants with a lower affinity for actin filament binding can still be functional, unless the affinity for actin monomers is also affected. The G-actin binding activity of the ADF plays an essential role in actin binding, depolymerization of actin polymers, and therefore in the control of actin organization.

Dong CH, Tang WP, Liu JY (2013) Arabidopsis AtADF1 is functionally affected by mutations on actin binding sites. J. Integr. Plant Biol. 55(3), 250–261.

Key words: Actin binding site, actin depolymerizing factor (ADF), Arabidopsis thaliana, mutation

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2021 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q
备案号:京ICP备16067583号-22