title: Caenorhabditis elegans gelsolin-like protein 1 is a novel actin filament-severing protein with four gelsolin-like repeats.
abstract: The gelsolin family of proteins is a major class of actin regulatory proteins that sever, cap, and nucleate actin filaments in a calcium-dependent manner and are involved in various cellular processes. Typically, gelsolin-related proteins have three or six repeats of gelsolin-like (G) domain, and each domain plays a distinct role in severing, capping, and nucleation. The Caenorhabditis elegans gelsolin-like protein-1 (gsnl-1) gene encodes an unconventional gelsolin-related protein with four G domains. Sequence alignment suggests that GSNL-1 lacks two G domains that are equivalent to fourth and fifth G domains of gelsolin. In vitro, GSNL-1 severed actin filaments and capped the barbed end in a calcium-dependent manner. However, unlike gelsolin, GSNL-1 remained bound to the side of F-actin with a submicromolar affinity and did not nucleate actin polymerization, although it bound to G-actin with high affinity. These results indicate that GSNL-1 is a novel member of the gelsolin family of actin regulatory proteins and provide new insight into functional diversity and evolution of gelsolin-related proteins.
authors.affiliation: Department of Pathology, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Tuula
authors.initials: T
authors.lastname: Klaavuniemi
authors.forename: Sawako
authors.initials: S
authors.lastname: Yamashiro
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Ono
mesh_terms: D000199:Actins / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000502:physiology; D002118:Calcium / Q000737:chemistry; D018260:Gelsolin / Q000737:chemistry*; D052139:Intracellular Calcium-Sensing Proteins / Q000737:chemistry / Q000502:physiology*; D007700:Kinetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
chemical_list: D000199:Actins; D029742:Caenorhabditis elegans Proteins; C532447:GSNL-1 protein, C elegans; D018260:Gelsolin; D052139:Intracellular Calcium-Sensing Proteins; D002118:Calcium