Identification and Characterization of the Actin-Binding Motif of Phostensin

International Journal of Molecular Sciences

Tzu-Fan Wang⁵  Ning-Sheng Lai³  Kuang-Yung Huang³  Hsien-Lu Huang¹  Ming-Chi Lu³  Yu-Shan Lin⁵  Chun-Yu Chen⁵  Su-Qin Liu⁴  Ta-Hsien Lin² 

[1] Department of Nutrition and Health Science, Fooyin University, Kaohsiung 83102, Taiwan; E-Mail:;Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 11221, Taiwan;College of Medicine, Tzu-Chi University, Hualien 97004, Taiwan; E-Mails:;Section of Allergy, Immunology and Rheumatology, Department of Medicine, DaLin Tzu Chi Buddhist Hospital, Chia-Yi 62247, Taiwan; E-Mail:;Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan; E-Mails:

关键词: phostensin;    actin filament;    KIAA1949;    protein phosphatase 1;   

DOI  :  10.3390/ijms131215967

来源: mdpi

【 摘 要 】

Phostensin, a protein phosphatase 1 F-actin cytoskeleton-targeting subunit encoded by KIAA1949, consists of 165 amino acids and caps the pointed ends of actin filaments. Sequence alignment analyses suggest that the C-terminal region of phostensin, spanning residues 129 to 155, contains a consensus actin-binding motif. Here, we have verified the existence of an actin-binding motif in the C-terminal domain of phostensin using colocalization, F-actin co-sedimentation and single filament binding assays. Our data indicate that the N-terminal region of phostensin (1–129) cannot bind to actin filaments and cannot retard the pointed end elongation of gelsolin-actin seeds. Furthermore, the C-terminal region of phostensin (125–165) multiply bind to the sides of actin filaments and lacks the ability to block the pointed end elongation, suggesting that the actin-binding motif is located in the C-terminal region of the phostensin. Further analyses indicate that phostensin binding to the pointed end of actin filament requires N-terminal residues 35 to 51. These results suggest that phostensin might fold into a rigid structure, allowing the N-terminus to sterically hinder the binding of C-terminus to the sides of actin filament, thus rendering phostensin binding to the pointed ends of actin filaments.

【 授权许可】

CC BY   
© 2012 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.