title: Localization of selenium-binding protein at the tips of rapidly extending protrusions.
abstract: Cell protrusive motility underlies cell fundamental biological processes such as cell growth, locomotion, and migration. Here I showed that selenium-binding protein (SBP) was exclusively located at the leading edges of rapidly growing protrusions in newly plated T98G glioma cells, and at the growing tips of the neurites in SH-SY5Y neuroblastoma cells. Double staining by anti-SBP antibody and deoxyribonuclease (DNase I) that labels monomeric G-actin or phalloidin that labels filamentous F-actin showed that the SBP-positive area was overstained by DNase I but, surprisingly, was not stained by phalloidin. When the cells were incubated with chemicals which block actin polymerization or activity of phosphatidylinositol 3-kinase, recruitment of SBP and G-actin at the cell margin was still observed, showing that their recruitment precedes actin polymerization. Taken together, I suggest that SBP may be involved in the initial sequential events in rapid cell outgrowth, such as determining direction of cell outgrowth and recruitment of actin monomer.
authors.affiliation: Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, 565-0871, Osaka, Japan, kmiyagu@neurol.med.osaka-u.ac.jp
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Miyaguchi
mesh_terms: D000199:Actins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D022081:Cell Surface Extensions / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D015638:Cytochalasin D / Q000494:pharmacology; D003850:Deoxyribonuclease I / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D016501:Neurites / Q000737:chemistry; D010590:Phalloidine / Q000737:chemistry; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011554:Pseudopodia / Q000737:chemistry; D051137:Selenium-Binding Proteins; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines
chemical_list: D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002352:Carrier Proteins; D000081082:Phosphoinositide-3 Kinase Inhibitors; C495175:SELENBP1 protein, human; D051137:Selenium-Binding Proteins; D013844:Thiazoles; D053778:Thiazolidines; D010590:Phalloidine; D015638:Cytochalasin D; D003850:Deoxyribonuclease I; C037067:latrunculin A