Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi, Taiwan.
J Histochem Cytochem. 2011 Aug;59(8):741-9. doi: 10.1369/0022155411411303.
Phostensin binds to the pointed ends of actin filaments and modulates actin dynamics. The genomic location of phostensin is between the HLA-C and HLA-E gene clusters on human chromosome 6, and the mRNA of this protein is predominantly distributed in the spleen, thymus, and peripheral leukocytes. However, the distribution of phostensin in leukocyte cell populations and the subcellular localization have not yet been determined. In this study, an anti-phostensin monoclonal antibody (PT2) that recognizes residues 89-124 of phostensin was prepared and used to examine the subcellular localization and distribution of phostensin in white blood cell populations and in lymphatic tissues. It was found that phostensin is mainly concentrated at the cell periphery and co-localizes with actin filaments. In addition, phostensin was abundant in helper T-lymphocytes, cytotoxic T-lymphocytes, mature monocytes, macrophages, B-lymphocytes, natural killer cells, and granulocytes as well as in the lymphatic tissues, such as the thymus, lymph nodes, and spleen. Phostensin is expressed in the mature lymphocytes of the thymic medulla but not in the immature lymphocytes of the thymic cortex. Taken together, phostensin is a ubiquitous protein in leukocytes, and it may play an important role in modulating the cellular functions of leukocytes.
磷蛋白结合到肌动蛋白纤维的尖端并调节肌动蛋白的动态。磷蛋白的基因组位置位于人类 6 号染色体上 HLA-C 和 HLA-E 基因簇之间，该蛋白的 mRNA 主要分布在脾脏、胸腺和外周白细胞中。然而，磷蛋白在白细胞群体中的分布和亚细胞定位尚未确定。在这项研究中，制备了一种识别磷蛋白 89-124 残基的抗磷蛋白单克隆抗体（PT2），并用于检查白细胞群体和淋巴组织中磷蛋白的亚细胞定位和分布。结果发现，磷蛋白主要集中在细胞外周，并与肌动蛋白纤维共定位。此外，磷蛋白在辅助性 T 淋巴细胞、细胞毒性 T 淋巴细胞、成熟单核细胞、巨噬细胞、B 淋巴细胞、自然杀伤细胞和粒细胞以及胸腺、淋巴结和脾脏等淋巴组织中丰富表达。磷蛋白在胸腺髓质的成熟淋巴细胞中表达，但不在胸腺皮质的未成熟淋巴细胞中表达。综上所述，磷蛋白是白细胞中普遍存在的一种蛋白，它可能在调节白细胞的细胞功能方面发挥重要作用。
