title: Identification of the high molecular weight isoform of phostensin.
abstract: Phostensin is encoded by KIAA1949. 5'-RACEanalysis has been used to identify the translation start site of phostensin mRNA, indicating that it encodes 165 amino acids with an apparent molecular weight of 26 kDa on SDS-PAGE. This low-molecular-weight phostensin is present in human peripheral blood mononuclear cells and many leukemic cell lines. Phostensin is a protein phosphatase-1(PP1) binding protein. It also contains one actin-binding motif at its C-terminal region and binds to the pointed ends of actin filaments, modulating actin dynamics. In the current study, a high-molecular-weight phostensin is identified by using immunoprecipitationin combination with a proteomic approach. This new species of phostensin is also encoded by KIAA1949 and consists of 613 amino acids with an apparent molecular weight of 110 kDa on SDS-PAGE. The low-molecular-weight and high-molecular-weight phostensins were named as phostensin-α and phostensin-β, respectively. Although phostensin-α is the C-terminal region of phostensin-β, it is not degraded from phostensin-β. Phostensin-β is capable of associating with PP1 and actin filaments, and is present in many cell lines.
authors.affiliation: Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. lambdaphagecarol@yahoo.com.tw.
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Lin
authors.affiliation: Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. estrus@mail2000.com.tw.
authors.forename: Hsien-Lu
authors.initials: HL
authors.lastname: Huang
authors.affiliation: Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. weiting0608@hotmail.com.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Liu
authors.affiliation: Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. thlin@vghtpe.gov.tw.
authors.forename: Ta-Hsien
authors.initials: TH
authors.lastname: Lin
authors.affiliation: Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. biohbh@ccu.edu.tw.
authors.forename: Hsien-Bin
authors.initials: HB
authors.lastname: Huang
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D057809:HEK293 Cells; D006801:Humans; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054645:Protein Phosphatase 1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D020033:Protein Isoforms; D012333:RNA, Messenger; C520010:PPP1R18 protein, human; D054645:Protein Phosphatase 1