PTEN regulates motility but not directionality during leukocyte chemotaxis

• Published in: Journal of cell science Vol. 117; no. Pt 25; pp. 6207 - 6215
• Main Authors: Lacalle, Rosa Ana, Gómez-Moutón, Concepción, Barber, Domingo F, Jiménez-Baranda, Sonia, Mira, Emilia, Martínez-A, Carlos, Carrera, Ana C, Mañes, Santos
• Format: Journal Article
• Language: English
• Published: England 01-12-2004
• Subjects: Actins - metabolism; Blotting, Western; Catalysis; Cell Movement; Chemotactic Factors - pharmacology; Chemotaxis; Cloning, Molecular; Cytoplasm - metabolism; Cytosol - metabolism; Dictyostelium; DNA, Complementary - metabolism; Dose-Response Relationship, Drug; Green Fluorescent Proteins - metabolism; HL-60 Cells; Humans; Jurkat Cells; Leukocytes - cytology; Membrane Microdomains - metabolism; Microscopy, Fluorescence; Microscopy, Video; Phosphatidylinositol 3-Kinases - metabolism; Phosphoric Monoester Hydrolases - metabolism; Phosphoric Monoester Hydrolases - physiology; Protein Structure, Tertiary; PTEN Phosphohydrolase; RNA, Small Interfering - metabolism; Subcellular Fractions - metabolism; Time Factors; Tumor Suppressor Proteins - metabolism; Tumor Suppressor Proteins - physiology
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.01545

The localization at opposite cell poles of phosphatidylinositol-3 kinases and PTEN (phosphatase and tensin homolog on chromosome 10) governs Dictyostelium chemotaxis. To study this model in mammalian cells, we analyzed the dynamic redistribution of green fluorescent protein (GFP)-tagged PTEN chimeras during chemotaxis. N- or C-terminus GFP-tagged PTEN was distributed homogeneously in the cytoplasm of chemotaxing PTEN-negative Jurkat cells and PTEN-positive HL60 cells. Moreover, we did not detect uropod accumulation of endogenous PTEN in chemoattractant-stimulated HL60 cells. Cell fractionation indicated that both endogenous and ectopically expressed PTEN were confined largely to the cytosol, and that chemoattractant stimulation did not alter this location. PTEN re-expression in Jurkat cells or PTEN depletion by specific siRNA in HL60 cells did not affect cell gradient sensing; PTEN nonetheless modulated chemoattractant-induced actin polymerization and the speed of cell movement. The results suggest a role for PTEN in regulating actin polymerization, but not directionality during mammalian cell chemotaxis.