TY - JOUR
T1 - Phosphorylation of the heat shock-related protein, HSP20, mediates cyclic nucleotide-dependent relaxation
AU - Woodrum, David
AU - Pipkin, Walter
AU - Tessier, Deron
AU - Komalavilas, Padmini
AU - Brophy, Colleen M.
N1 - Funding Information:
Supported by a VA Merit Review Award and NIH RO1 HL58027-01.
PY - 2003/4/1
Y1 - 2003/4/1
N2 - Cyclic nucleotide-dependent relaxation of vascular smooth muscle is associated with increases in the phosphorylation of the small heat shock-related protein, HSP20. To determine whether phosphorylated HSP20 directly mediates relaxation, we used gene transfection and protein transduction of HSP20 analogues. Rat mesangial cells were transfected with constructs containing wild-type HSP20-enhanced green fluorescent protein (EGFP), phosphorylation site mutated HSP20 (S16A-HSP20-EGFP), or EGFP alone. Contractile properties were determined on a silicone polymer substrata. In the presence of serum, EGFP-vector transfected control cells and S16A-HSP20 transfected cells formed wrinkles on the polymer (contracted). Activation of cyclic nucleotide signaling pathways in the EGFP-vector transfected control cells led to a time-dependent decrease in the wrinkles (relaxation). The S16A-HSP20 transfected cells were refractory to cyclic nucleotide-dependent relaxation. Cells overexpressing the wild-type HSP20 did not form wrinkles on the polymer in response to serum (refractory to contraction). Treatment of precontracted strips of intact bovine carotid artery smooth muscle with synthetic peptides containing HIV-trans-activating transcriptional activator and a phosphopeptide motif of HSP20 led to dose-dependent relaxation. These data provide evidence that phosphorylated HSP20 has a direct role in smooth muscle relaxation and that small phosphopeptide motifs of HSP20 can mimic the effects of the entire molecule.
AB - Cyclic nucleotide-dependent relaxation of vascular smooth muscle is associated with increases in the phosphorylation of the small heat shock-related protein, HSP20. To determine whether phosphorylated HSP20 directly mediates relaxation, we used gene transfection and protein transduction of HSP20 analogues. Rat mesangial cells were transfected with constructs containing wild-type HSP20-enhanced green fluorescent protein (EGFP), phosphorylation site mutated HSP20 (S16A-HSP20-EGFP), or EGFP alone. Contractile properties were determined on a silicone polymer substrata. In the presence of serum, EGFP-vector transfected control cells and S16A-HSP20 transfected cells formed wrinkles on the polymer (contracted). Activation of cyclic nucleotide signaling pathways in the EGFP-vector transfected control cells led to a time-dependent decrease in the wrinkles (relaxation). The S16A-HSP20 transfected cells were refractory to cyclic nucleotide-dependent relaxation. Cells overexpressing the wild-type HSP20 did not form wrinkles on the polymer in response to serum (refractory to contraction). Treatment of precontracted strips of intact bovine carotid artery smooth muscle with synthetic peptides containing HIV-trans-activating transcriptional activator and a phosphopeptide motif of HSP20 led to dose-dependent relaxation. These data provide evidence that phosphorylated HSP20 has a direct role in smooth muscle relaxation and that small phosphopeptide motifs of HSP20 can mimic the effects of the entire molecule.
UR - http://www.scopus.com/inward/record.url?scp=0037380749&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037380749&partnerID=8YFLogxK
U2 - 10.1067/mva.2003.153
DO - 10.1067/mva.2003.153
M3 - Article
C2 - 12663991
AN - SCOPUS:0037380749
SN - 0741-5214
VL - 37
SP - 874
EP - 881
JO - Journal of vascular surgery
JF - Journal of vascular surgery
IS - 4
ER -