1. The Protein Tyrosine Phosphatase PTP-BL Associates with the Midbody and Is Involved in the Regulation of Cytokinesis
- Author
-
Kai S. Erdmann, Thomas Dittmar, and Lutz Herrmann
- Subjects
animal structures ,Recombinant Fusion Proteins ,PDZ domain ,Protein Tyrosine Phosphatase, Non-Receptor Type 13 ,Protein tyrosine phosphatase ,Biology ,Microtubules ,environment and public health ,Filamentous actin ,Article ,Genes, Reporter ,Tubulin ,Guanine Nucleotide Exchange Factors ,Humans ,Telophase ,Molecular Biology ,Actin ,Centrosome ,FERM domain ,Spindle midzone ,Cell Biology ,Actins ,Cell biology ,enzymes and coenzymes (carbohydrates) ,Midbody ,Protein Tyrosine Phosphatases ,Cell Division ,Rho Guanine Nucleotide Exchange Factors ,Cytokinesis ,HeLa Cells - Abstract
PTP-BL is a highly modular protein tyrosine phosphatase of unknown function. It consists of an N-terminal FERM domain, five PDZ domains, and a C-terminally located tyrosine phosphatase domain. Here we show that PTP-BL is involved in the regulation of cytokinesis. We demonstrate localization of endogenous PTP-BL at the centrosomes during inter- and metaphase and at the spindle midzone during anaphase. Finally PTP-BL is concentrated at the midbody in cytokinesis. We show that PTP-BL is targeted to the midbody and centrosome by a specific splicing variant of the N-terminus characterized by an insertion of 182 amino acids. Moreover, we demonstrate that the FERM domain of PTP-BL is associated with the contractile ring and can be cosedimented with filamentous actin, whereas the N-terminus can be cosedimented with microtubules. We demonstrate that elevating the expression level of wild-type PTP-BL or expression of PTP-BL with an inactive tyrosine phosphatase domain leads to defects in cytokinesis and to the generation of multinucleate cells. We suggest that PTP-BL plays a role in the regulation of cytokinesis.
- Published
- 2003