1. Academic Validation
  2. Identification of the high molecular weight isoform of phostensin

Identification of the high molecular weight isoform of phostensin

  • Int J Mol Sci. 2014 Jan 15;15(1):1068-79. doi: 10.3390/ijms15011068.
Yu-Shan Lin 1 Hsien-Lu Huang 2 Wei-Ting Liu 3 Ta-Hsien Lin 4 Hsien-Bin Huang 5
Affiliations

Affiliations

  • 1 Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. lambdaphagecarol@yahoo.com.tw.
  • 2 Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. estrus@mail2000.com.tw.
  • 3 Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. weiting0608@hotmail.com.
  • 4 Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. thlin@vghtpe.gov.tw.
  • 5 Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan. biohbh@ccu.edu.tw.
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.

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