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Title: Erk1/2 MAPK and caldesmon differentially regulate podosome dynamics in A7r5 vascular smooth muscle cells

Abstract

We tested the hypothesis that the MEK/Erk/caldesmon phosphorylation cascade regulates PKC-mediated podosome dynamics in A7r5 cells. We observed the phosphorylation of MEK, Erk and caldesmon, and their translocation to the podosomes upon phorbol dibutyrate (PDBu) stimulation, together with the nuclear translocation of phospho-MEK and phospho-Erk. After MEK inhibition by U0126, Erk translocated to the interconnected actin-rich columns but failed to translocate to the nucleus, suggesting that podosomes served as a site for Erk phosphorylation. The interconnected actin-rich columns in U0126-treated, PDBu-stimulated cells contained {alpha}-actinin, caldesmon, vinculin, and metalloproteinase-2. Caldesmon and vinculin became integrated with F-actin at the columns, in contrast to their typical location at the ring of podosomes. Live-imaging experiments suggested the growth of these columns from podosomes that were slow to disassemble. The observed modulation of podosome size and life time in A7r5 cells overexpressing wild-type and phosphorylation-deficient caldesmon-GFP mutants in comparison to untransfected cells suggests that caldesmon and caldesmon phosphorylation modulate podosome dynamics in A7r5 cells. These results suggest that Erk1/2 and caldesmon differentially modulate PKC-mediated formation and/or dynamics of podosomes in A7r5 vascular smooth muscle cells.

Authors:
 [1];  [2];  [3];  [2];  [4]
  1. Department of Molecular Pharmacology, Physiology and Biotechnology, Box G-B3, Brown University, Providence, RI 02912 (United States)
  2. Boston Biomedical Research Institute, Watertown, MA 02472 (United States)
  3. Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912 (United States)
  4. Department of Molecular Pharmacology, Physiology and Biotechnology, Box G-B3, Brown University, Providence, RI 02912 (United States). E-mail: Chi-Ming_Hai@brown.edu
Publication Date:
OSTI Identifier:
20972125
Resource Type:
Journal Article
Resource Relation:
Journal Name: Experimental Cell Research; Journal Volume: 313; Journal Issue: 5; Other Information: DOI: 10.1016/j.yexcr.2006.12.005; PII: S0014-4827(06)00498-8; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ACTIN; ARTERIOSCLEROSIS; CELL NUCLEI; INHIBITION; MICROTUBULES; MODULATION; MUSCLES; MUTANTS; PHOSPHORYLATION; TRANSLOCATION

Citation Formats

Gu Zhizhan, Kordowska, Jolanta, Williams, Geoffrey L., Wang, C.-L. Albert, and Hai, C.-M. Erk1/2 MAPK and caldesmon differentially regulate podosome dynamics in A7r5 vascular smooth muscle cells. United States: N. p., 2007. Web.
Gu Zhizhan, Kordowska, Jolanta, Williams, Geoffrey L., Wang, C.-L. Albert, & Hai, C.-M. Erk1/2 MAPK and caldesmon differentially regulate podosome dynamics in A7r5 vascular smooth muscle cells. United States.
Gu Zhizhan, Kordowska, Jolanta, Williams, Geoffrey L., Wang, C.-L. Albert, and Hai, C.-M. Sat . "Erk1/2 MAPK and caldesmon differentially regulate podosome dynamics in A7r5 vascular smooth muscle cells". United States. doi:.
@article{osti_20972125,
title = {Erk1/2 MAPK and caldesmon differentially regulate podosome dynamics in A7r5 vascular smooth muscle cells},
author = {Gu Zhizhan and Kordowska, Jolanta and Williams, Geoffrey L. and Wang, C.-L. Albert and Hai, C.-M.},
abstractNote = {We tested the hypothesis that the MEK/Erk/caldesmon phosphorylation cascade regulates PKC-mediated podosome dynamics in A7r5 cells. We observed the phosphorylation of MEK, Erk and caldesmon, and their translocation to the podosomes upon phorbol dibutyrate (PDBu) stimulation, together with the nuclear translocation of phospho-MEK and phospho-Erk. After MEK inhibition by U0126, Erk translocated to the interconnected actin-rich columns but failed to translocate to the nucleus, suggesting that podosomes served as a site for Erk phosphorylation. The interconnected actin-rich columns in U0126-treated, PDBu-stimulated cells contained {alpha}-actinin, caldesmon, vinculin, and metalloproteinase-2. Caldesmon and vinculin became integrated with F-actin at the columns, in contrast to their typical location at the ring of podosomes. Live-imaging experiments suggested the growth of these columns from podosomes that were slow to disassemble. The observed modulation of podosome size and life time in A7r5 cells overexpressing wild-type and phosphorylation-deficient caldesmon-GFP mutants in comparison to untransfected cells suggests that caldesmon and caldesmon phosphorylation modulate podosome dynamics in A7r5 cells. These results suggest that Erk1/2 and caldesmon differentially modulate PKC-mediated formation and/or dynamics of podosomes in A7r5 vascular smooth muscle cells.},
doi = {},
journal = {Experimental Cell Research},
number = 5,
volume = 313,
place = {United States},
year = {Sat Mar 10 00:00:00 EST 2007},
month = {Sat Mar 10 00:00:00 EST 2007}
}