TY - JOUR
T1 - LIM kinase 1
T2 - Evidence for a role in the regulation of intracellular vesicle trafficking of lysosomes and endosomes in human breast cancer cells
AU - Nishimura, Yukio
AU - Yoshioka, Kiyoko
AU - Bernard, Ora
AU - Himeno, Masaru
AU - Itoh, Kazuyuki
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2004/8
Y1 - 2004/8
N2 - LIM kinase (LIMK) plays a critical role in stimulus-induced remodeling of the actin cytoskeleton by linking signals from the Rho family GTPases to changes in cofilin activity. Recent studies have shown an important role for LIMK1 signaling in tumor cell invasion through regulating actin dynamics. In this study, we investigate the role of LIMK1 in intracellular vesicle trafficking of lysosomes/endosomes. We analyzed by confocal immunofluorescence microscopy the cellular distribution of lysosomal proteins and the endocytosis of an endocytic tracer, epidermal growth factor (EGF), in LIMK1-transfected cells. We found in these cells an abnormal dispersed translocation of lysosomes stained for LIMPII and cathepsin D throughout the cytoplasm.The small punctate structures that stained for these lysosomal proteins were redistributed to the periphery of the cell. Computational 3D-image analysis of confocal immunofluorescence micrographs further demonstrated that these vesicles did not colocalize with the transferrin receptor, an early endosomal marker. Furthermore, LIMPII-positive lysosomes did not colocalize with early endosomes labeled with endocytosed Texas red-transferrin. These results indicate that there is no mixing between dispersed lysosomes and early endosomes in the LIMK1-transfected cells. Moreover, LIMK1 overexpression resulted in a marked retardation in the receptor-mediated internalization of Texas red-labeled EGF in comparison with mock-transfected cells. At 30 min after internalization, most of the Texas red-EGF staining overlapped with LIMPII-positive late endosomes/lysosomes in mock-transfected cells, whereas in LIMK1 transfectants only a small fraction of internalized EGF colocalized with LIMPII-positive structures in the perinuclear region. Taken together, the findings presented in this paper suggest that LIMK1 has a role in regulating vesicle trafficking of lysosomes and endosomes in invasive tumor cells.
AB - LIM kinase (LIMK) plays a critical role in stimulus-induced remodeling of the actin cytoskeleton by linking signals from the Rho family GTPases to changes in cofilin activity. Recent studies have shown an important role for LIMK1 signaling in tumor cell invasion through regulating actin dynamics. In this study, we investigate the role of LIMK1 in intracellular vesicle trafficking of lysosomes/endosomes. We analyzed by confocal immunofluorescence microscopy the cellular distribution of lysosomal proteins and the endocytosis of an endocytic tracer, epidermal growth factor (EGF), in LIMK1-transfected cells. We found in these cells an abnormal dispersed translocation of lysosomes stained for LIMPII and cathepsin D throughout the cytoplasm.The small punctate structures that stained for these lysosomal proteins were redistributed to the periphery of the cell. Computational 3D-image analysis of confocal immunofluorescence micrographs further demonstrated that these vesicles did not colocalize with the transferrin receptor, an early endosomal marker. Furthermore, LIMPII-positive lysosomes did not colocalize with early endosomes labeled with endocytosed Texas red-transferrin. These results indicate that there is no mixing between dispersed lysosomes and early endosomes in the LIMK1-transfected cells. Moreover, LIMK1 overexpression resulted in a marked retardation in the receptor-mediated internalization of Texas red-labeled EGF in comparison with mock-transfected cells. At 30 min after internalization, most of the Texas red-EGF staining overlapped with LIMPII-positive late endosomes/lysosomes in mock-transfected cells, whereas in LIMK1 transfectants only a small fraction of internalized EGF colocalized with LIMPII-positive structures in the perinuclear region. Taken together, the findings presented in this paper suggest that LIMK1 has a role in regulating vesicle trafficking of lysosomes and endosomes in invasive tumor cells.
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U2 - 10.1078/0171-9335-00382
DO - 10.1078/0171-9335-00382
M3 - Article
C2 - 15503860
AN - SCOPUS:4744337757
VL - 83
SP - 369
EP - 380
JO - European Journal of Cell Biology
JF - European Journal of Cell Biology
SN - 0171-9335
IS - 7
ER -