title: Homeoprotein Hbx4 represses the expression of the adhesion molecule DdCAD-1 governing cytokinesis and development.
abstract: We investigated the function of homeodomain-containing protein Hbx4 in Dictyostelium discoideum. Hbx4-overexpressing cells (Hbx4(OE)) displayed defects in growth rate and cytokinesis and showed differences in slug motility and cell-type proportioning from KAx3. Furthermore, the overexpression of Hbx4 inhibited the induction of cadA, which encoded the Ca(2+)-dependent cell adhesion molecule DdCAD-1, despite expression of csaA and gpaB. The electrophoretic mobility shift assay showed that the promoter of cadA contained the Hbx4-binding site. Moreover, constitutively expressed DdCAD-1 in Hbx4(OE) rescued the defects in cytokinesis and development. These results suggest that Hbx4 modulates DdCAD-1-mediated cytokinesis and cell-type proportioning.
authors.affiliation: Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul, Republic of Korea.
authors.forename: Ji-Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Ji-Hui
authors.initials: JH
authors.lastname: Seo
authors.forename: Hyung-Soon
authors.initials: HS
authors.lastname: Yim
authors.forename: Sa-Ouk
authors.initials: SO
authors.lastname: Kang
mesh_terms: D002135:Calcium-Binding Proteins / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000235:genetics*; D048749:Cytokinesis; D004023:Dictyostelium / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000502:physiology*; D015800:Protozoan Proteins / Q000502:physiology*
chemical_list: D002135:Calcium-Binding Proteins; D015815:Cell Adhesion Molecules; C100604:DdCAD-1 protein, Dictyostelium discoideum; D018398:Homeodomain Proteins; D015800:Protozoan Proteins