title: The plant-specific actin binding protein SCAB1 stabilizes actin filaments and regulates stomatal movement in Arabidopsis.
abstract: Microfilament dynamics play a critical role in regulating stomatal movement; however, the molecular mechanism underlying this process is not well understood. We report here the identification and characterization of STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1 (SCAB1), an Arabidopsis thaliana actin binding protein. Plants lacking SCAB1 were hypersensitive to drought stress and exhibited reduced abscisic acid-, H(2)O(2)-, and CaCl(2)-regulated stomatal movement. In vitro and in vivo analyses revealed that SCAB1 binds, stabilizes, and bundles actin filaments. SCAB1 shares sequence similarity only with plant proteins and contains a previously undiscovered actin binding domain. During stomatal closure, actin filaments switched from a radial orientation in open stomata to a longitudinal orientation in closed stomata. This switch took longer in scab1 plants than in wild-type plants and was correlated with the delay in stomatal closure seen in scab1 mutants in response to drought stress. Our results suggest that SCAB1 is required for the precise regulation of actin filament reorganization during stomatal closure.
authors: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors: Yang
authors: Y
authors: Zhao
authors: Shuangshuang
authors: S
authors: Zhao
authors: Tonglin
authors: T
authors: Mao
authors: Xiaolu
authors: X
authors: Qu
authors: Wanhong
authors: W
authors: Cao
authors: Li
authors: L
authors: Zhang
authors: Wei
authors: W
authors: Zhang
authors: Liu
authors: L
authors: He
authors: Sidi
authors: S
authors: Li
authors: Sulin
authors: S
authors: Ren
authors: Jinfeng
authors: J
authors: Zhao
authors: Guoli
authors: G
authors: Zhu
authors: Shanjin
authors: S
authors: Huang
authors: Keqiong
authors: K
authors: Ye
authors: Ming
authors: M
authors: Yuan
authors: Yan
authors: Y
authors: Guo
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002122:Calcium Chloride / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D008840:Microfilament Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D016877:Oxidants / Q000378:metabolism; D010802:Phylogeny; D054046:Plant Stomata / Q000378:metabolism* / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D008840:Microfilament Proteins; D016877:Oxidants; D011993:Recombinant Fusion Proteins; C570516:SCAB1 protein, Arabidopsis; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D002122:Calcium Chloride