title: The protein tyrosine phosphatase PTP-BL associates with the midbody and is involved in the regulation of cytokinesis.
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.
authors.affiliation: Department of Molecular Neurobiochemistry, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Herrmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Dittmar
authors.forename: Kai S
authors.initials: KS
authors.lastname: Erdmann
mesh_terms: D000199:Actins / Q000378:metabolism; D002455:Cell Division / Q000502:physiology*; D018385:Centrosome / Q000378:metabolism; D017930:Genes, Reporter; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000378:metabolism; D054595:Protein Tyrosine Phosphatase, Non-Receptor Type 13; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D064067:Rho Guanine Nucleotide Exchange Factors; D013692:Telophase / Q000502:physiology; D014404:Tubulin / Q000378:metabolism
chemical_list: D000199:Actins; C577426:FARP2 protein, human; D020662:Guanine Nucleotide Exchange Factors; D011993:Recombinant Fusion Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; D014404:Tubulin; C516742:PTPN13 protein, human; D054595:Protein Tyrosine Phosphatase, Non-Receptor Type 13; D017027:Protein Tyrosine Phosphatases