Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi 62102, Taiwan.
Int J Mol Sci. 2014 Jan 15;15(1):1068-79. doi: 10.3390/ijms15011068.
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.
磷酸丝氨酸由 KIAA1949 编码。5′-RACE 分析已被用于鉴定磷酸丝氨酸 mRNA 的翻译起始位点，表明其编码 165 个氨基酸，在 SDS-PAGE 上的表观分子量为 26 kDa。这种低分子量的磷酸丝氨酸存在于人外周血单核细胞和许多白血病细胞系中。磷酸丝氨酸是蛋白磷酸酶-1（PP1）结合蛋白。它还在 C 末端区域含有一个肌动蛋白结合基序，并与肌动蛋白丝的尖端结合，调节肌动蛋白动力学。在本研究中，通过免疫沉淀结合蛋白质组学方法鉴定了一种高分子量的磷酸丝氨酸。这种新的磷酸丝氨酸也由 KIAA1949 编码，由 613 个氨基酸组成，在 SDS-PAGE 上的表观分子量为 110 kDa。低分子量和高分子量的磷酸丝氨酸分别命名为磷酸丝氨酸-α和磷酸丝氨酸-β。尽管磷酸丝氨酸-α是磷酸丝氨酸-β的 C 末端区域，但它不是从磷酸丝氨酸-β中降解而来的。磷酸丝氨酸-β能够与 PP1 和肌动蛋白丝结合，并存在于许多细胞系中。
