PTEN regulates motility but not directionality during leukocyte chemotaxis.
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.
Lacalle
Rosa Ana
RA
Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, UAM Campus de Cantoblanco, 28049 Madrid, Spain.
Gómez-Moutón
Concepción
C
Barber
Domingo F
DF
Jiménez-Baranda
Sonia
S
Mira
Emilia
E
Martínez-A
Carlos
C
Carrera
Ana C
AC
Mañes
Santos
S
D000199:Actins / Q000378:metabolism; D015153:Blotting, Western; D002384:Catalysis; D002465:Cell Movement; D002630:Chemotactic Factors / Q000494:pharmacology; D002633:Chemotaxis; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D019169:Jurkat Cells; D007962:Leukocytes / Q000166:cytology*; D021962:Membrane Microdomains / Q000378:metabolism; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism / Q000502:physiology*; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D025521:Tumor Suppressor Proteins / Q000378:metabolism / Q000502:physiology*
D000199:Actins; D002630:Chemotactic Factors; D018076:DNA, Complementary; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; D049452:Green Fluorescent Proteins; D019869:Phosphatidylinositol 3-Kinases; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human