title: A pleckstrin homology-like domain is critical for F-actin binding and cofilin-phosphatase activity of Slingshot-1.
abstract: Slingshot-1 (SSH1) is a protein phosphatase that specifically dephosphorylates and activates cofilin, an F-actin-severing protein. SSH1 binds to and co-localizes with F-actin, and the cofilin-phosphatase activity of SSH1 is markedly increased by binding to F-actin. In this study, we performed a secondary structure analysis of SSH1, which predicted the existence of a pleckstrin homology (PH)-like domain in the N-terminal region of SSH1. SSH1 also contains a DEK-C domain in the N-terminal region. The N-terminal fragment of SSH1 bound to and co-localized with F-actin, but mutation at Arg-96 or a Leu-His-Lys (LHK) motif in the PH-like domain reduced this activity. Furthermore, mutation at Arg-96 abrogated the cofilin-phosphatase activity of SSH1 in the presence of F-actin. These results suggest that the N-terminal PH-like domain plays a critical role in F-actin binding and F-actin-mediated activation of the cofilin-phosphatase activity of SSH1.
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Okabe
authors.affiliation: Division of Dynamic Proteome in Cancer and Aging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi 980-8575, Japan.
authors.forename: Shin-Ichiro
authors.initials: SI
authors.lastname: Kanno
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Nagai
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan. Electronic address: kmizuno@biology.tohoku.ac.jp.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mizuno
mesh_terms: D051339:Actin Depolymerizing Factors / Q000737:chemistry*; D000199:Actins / Q000737:chemistry*; D020816:Amino Acid Motifs; D000818:Animals; D020134:Catalytic Domain; D002942:Circular Dichroism; D057809:HEK293 Cells; D006367:HeLa Cells; D006639:Histidine / Q000737:chemistry; D006801:Humans; D007930:Leucine / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D018482:Muscle, Skeletal / Q000378:metabolism; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000737:chemistry*; D010957:Plasmids / Q000378:metabolism; D000070539:Pleckstrin Homology Domains; D011485:Protein Binding; D011817:Rabbits
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D006639:Histidine; D010749:Phosphoprotein Phosphatases; C484329:SSH1 protein, human; D007930:Leucine; D008239:Lysine
keywords: Actin binding; Cofilin; Phosphatase; Pleckstrin homology (PH) domain; Slingshot