title: Immunolocalization of phostensin in lymphatic cells and tissues.
abstract: 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.
authors.affiliation: Department of Life Science and Institute of Molecular Biology, National Chung Cheng University, Chia-Yi, Taiwan.
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Lin
authors.forename: Kuang-Yung
authors.initials: KY
authors.lastname: Huang
authors.forename: Tzu-Fan
authors.initials: TF
authors.lastname: Wang
authors.forename: Hsien-lu
authors.initials: HL
authors.lastname: Huang
authors.forename: Hui-Chun
authors.initials: HC
authors.lastname: Yu
authors.forename: Jia-yi
authors.initials: JY
authors.lastname: Yen
authors.forename: Shih-hui
authors.initials: SH
authors.lastname: Hung
authors.forename: Su-Qin
authors.initials: SQ
authors.lastname: Liu
authors.forename: Ning-Sheng
authors.initials: NS
authors.lastname: Lai
authors.forename: Hsien-bin
authors.initials: HB
authors.lastname: Huang
mesh_terms: D000911:Antibodies, Monoclonal; D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007938:Leukemia; D007962:Leukocytes / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008221:Lymphoid Tissue / Q000378:metabolism*; D054645:Protein Phosphatase 1 / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; C520010:PPP1R18 protein, human; D054645:Protein Phosphatase 1