title: Platelet-activating factor (PAF) activates casein kinase 2 in the protozoan parasite Herpetomonas muscarum muscarum.
abstract: Herpetomonas muscarum muscarum is a flagellate parasite of the family Trypanosomatidae, whose cell differentiation can be triggered by the lipid mediator, PAF. In this study we demonstrate for the first time that PAF effect relies on the activation of casein kinase 2 (CK2). The classical antagonist of PAF receptor, WEB 2086, abrogated PAF-enhanced CK2 activity. CK2 activation by PAF was also inhibited when parasite extracts were assayed in the presence of modulators of PKC, MAPK, and both Ser/Thr and Tyr phosphatases. Finally, a cell permeable inhibitor of CK2 (DRB) suppressed PAF-induced cell differentiation in a dose-dependent manner.
authors.affiliation: Departamento de Bioquímica Médica, ICB, CCS, Universidade Federal do Rio de Janeiro, UFRJ, P.O. Box 68041, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, CEP 21941-590, RJ, Brazil. maneto@bioqmed.ufrj.br
authors.forename: Mário A C
authors.initials: MA
authors.lastname: Silva-Neto
authors.forename: Alan B
authors.initials: AB
authors.lastname: Carneiro
authors.forename: Danielle P
authors.initials: DP
authors.lastname: Vieira
authors.forename: Rafael D
authors.initials: RD
authors.lastname: Mesquita
authors.forename: Angela H C S
authors.initials: AH
authors.lastname: Lopes
mesh_terms: D000818:Animals; D015153:Blotting, Western; D047390:Casein Kinase II; D002454:Cell Differentiation; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D010766:Phosphorylation; D010972:Platelet Activating Factor / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014351:Trypanosomatina / Q000201:enzymology*
chemical_list: D010972:Platelet Activating Factor; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases