Abstract
The renal cell line mIMCD3 exhibits markedly upregulated phosphorylation of the extracellular signal-regulated kinase (ERK) 1 and 2 in response to urea treatment (200 mM for 5 min). Previous data have suggested the involvement of a classical protein kinase C (cPKC)-dependent pathway in downstream events related to urea signaling. We now show that urea-inducible ERK activation requires extracellular calcium; unexpectedly, it occurs independently of activation of cPKC isoforms. Pharmacological inhibitors of known intracellular calcium release pathways and extracellular calcium entry pathways fail to inhibit ERK activation by urea. Fura 2 ratiometry was used to assess the effect of urea treatment on intracellular calcium mobilization. In single-cell analyses using subconfluent monolayers and in population-wide analyses using both confluent monolayers and cells in suspension, urea failed to increase intracellular calcium concentration. Taken together, these data indicate that urea-inducible ERK activation requires calcium action but not calcium entry. Although direct evidence is lacking, one possible explanation could include involvement of a calcium-dependent extracellular moiety of a cell surface-associated protein.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Renal Physiology |
| Volume | 280 |
| Issue number | 1 49-1 |
| State | Published - Jan 2001 |
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Keywords
- Fura 2
- Hypotonicity
- Inner medullary collecting duct
- Madin-Darby canine kidney
- Protein kinase C
ASJC Scopus subject areas
- Physiology
- Physiology (medical)
Cite this
Urea signaling to ERK phosphorylation in renal medullary cells requires extracellular calcium but not calcium entry. / Yang, Xiao Yan; Zhao, Hongyu; Zhang, Zheng; Rodland, Karin D.; Roullet, Jean-Baptiste; Cohen, David.
In: American Journal of Physiology - Renal Physiology, Vol. 280, No. 1 49-1, 01.2001.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Urea signaling to ERK phosphorylation in renal medullary cells requires extracellular calcium but not calcium entry
AU - Yang, Xiao Yan
AU - Zhao, Hongyu
AU - Zhang, Zheng
AU - Rodland, Karin D.
AU - Roullet, Jean-Baptiste
AU - Cohen, David
PY - 2001/1
Y1 - 2001/1
N2 - The renal cell line mIMCD3 exhibits markedly upregulated phosphorylation of the extracellular signal-regulated kinase (ERK) 1 and 2 in response to urea treatment (200 mM for 5 min). Previous data have suggested the involvement of a classical protein kinase C (cPKC)-dependent pathway in downstream events related to urea signaling. We now show that urea-inducible ERK activation requires extracellular calcium; unexpectedly, it occurs independently of activation of cPKC isoforms. Pharmacological inhibitors of known intracellular calcium release pathways and extracellular calcium entry pathways fail to inhibit ERK activation by urea. Fura 2 ratiometry was used to assess the effect of urea treatment on intracellular calcium mobilization. In single-cell analyses using subconfluent monolayers and in population-wide analyses using both confluent monolayers and cells in suspension, urea failed to increase intracellular calcium concentration. Taken together, these data indicate that urea-inducible ERK activation requires calcium action but not calcium entry. Although direct evidence is lacking, one possible explanation could include involvement of a calcium-dependent extracellular moiety of a cell surface-associated protein.
AB - The renal cell line mIMCD3 exhibits markedly upregulated phosphorylation of the extracellular signal-regulated kinase (ERK) 1 and 2 in response to urea treatment (200 mM for 5 min). Previous data have suggested the involvement of a classical protein kinase C (cPKC)-dependent pathway in downstream events related to urea signaling. We now show that urea-inducible ERK activation requires extracellular calcium; unexpectedly, it occurs independently of activation of cPKC isoforms. Pharmacological inhibitors of known intracellular calcium release pathways and extracellular calcium entry pathways fail to inhibit ERK activation by urea. Fura 2 ratiometry was used to assess the effect of urea treatment on intracellular calcium mobilization. In single-cell analyses using subconfluent monolayers and in population-wide analyses using both confluent monolayers and cells in suspension, urea failed to increase intracellular calcium concentration. Taken together, these data indicate that urea-inducible ERK activation requires calcium action but not calcium entry. Although direct evidence is lacking, one possible explanation could include involvement of a calcium-dependent extracellular moiety of a cell surface-associated protein.
KW - Fura 2
KW - Hypotonicity
KW - Inner medullary collecting duct
KW - Madin-Darby canine kidney
KW - Protein kinase C
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UR - http://www.scopus.com/inward/citedby.url?scp=0035009188&partnerID=8YFLogxK
M3 - Article
VL - 280
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 1 49-1
ER -