title: Gelsolin-Like Domain 3 Plays Vital Roles in Regulating the Activities of the Lily Villin/Gelsolin/Fragmin Superfamily.
abstract: The villin/gelsolin/fragmin superfamily is a major group of Ca2+-dependent actin-binding proteins (ABPs) involved in various cellular processes. Members of this superfamily typically possess three or six tandem gelsolin-like (G) domains, and each domain plays a distinct role in actin filament dynamics. Although the activities of most G domains have been characterized, the biochemical function of the G3 domain remains poorly understood. In this study, we carefully compared the detailed biochemical activities of ABP29 (a new member of this family that contains the G1-G2 domains of lily ABP135) and ABP135G1-G3 (which contains the G1-G3 domains of lily ABP135). In the presence of high Ca2+ levels in vitro (200 and 10 μM), ABP135G1-G3 exhibited greater actin severing and/or depolymerization and nucleating activities than ABP29, and these proteins had similar actin capping activities. However, in the presence of low levels of Ca2+ (41 nM), ABP135G1-G3 had a weaker capping activity than ABP29. In addition, ABP29 inhibited F-actin depolymerization, as shown by dilution-mediated depolymerization assay, differing from the typical superfamily proteins. In contrast, ABP135G1-G3 accelerated F-actin depolymerization. All of these results demonstrate that the G3 domain plays specific roles in regulating the activities of the lily villin/gelsolin/fragmin superfamily proteins.
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Qian
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Nan
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yuelong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Jingen
authors.initials: J
authors.lastname: Zhu
authors.affiliation: College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Bai
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Pan
authors.initials: P
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Lizhe
authors.initials: L
authors.lastname: An
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry; D000199:Actins / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D017985:Dalteparin / Q000737:chemistry; D018260:Gelsolin / Q000737:chemistry*; D006801:Humans; D027762:Lilium / Q000737:chemistry; D008840:Microfilament Proteins / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D005810:Multigene Family; D018482:Muscle, Skeletal / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D000199:Actins; D018076:DNA, Complementary; D018260:Gelsolin; D008840:Microfilament Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C026615:villin; D017985:Dalteparin; D002118:Calcium