Abstract
Insulin secretion from pancreatic β-cells has to be tightly regulated to ensure accurate glucose homeostasis. The capacity of β-cells to respond to extracellular stimulation is determined by several signaling pathways. One important feature of these pathways is phosphorylation and subsequent dephosphorylation of a wide range of cellular substrates. Protein phosphatase 1 (PP1) is a major eukaryotic serine/threonine protein phosphatase that controls a multitude of physiological processes. We have investigated the expression and cellular distribution of two endogenous inhibitors of PP1 activity in β-cells. RT-PCR, Western blotting, and immunohistochemistry showed that DARPP-32 and inhibitor-1 are present in insulin-secreting endocrine β-cells. Subcellular fractionation of mouse islets revealed that both PP1 inhibitors predominantly localized to cytosol-enriched fractions. Inhibitor-1 was also present in fractions containing plasma membrane-associated proteins. These data indicate a potential role for DARPP-32 and inhibitor-1 in the regulation of PP1 activity in pancreatic β-cell stimulus-secretion coupling.
| Original language | English |
|---|---|
| Pages (from-to) | 673-677 |
| Number of pages | 5 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 329 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 8 2005 |
| Externally published | Yes |
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Keywords
- Dephosphorylation
- Exocytosis
- Immunohistochemistry
- Insulin
- Phosphatase
- PP1 inhibitor
- RT-PCR
- Secretion
- Subcellular fractionation
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology
Cite this
DARPP-32 and inhibitor-1 are expressed in pancreatic β-cells. / Lilja, Lena; Meister, Björn; Berggren, Per Olof; Bark, Christina.
In: Biochemical and Biophysical Research Communications, Vol. 329, No. 2, 08.04.2005, p. 673-677.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - DARPP-32 and inhibitor-1 are expressed in pancreatic β-cells
AU - Lilja, Lena
AU - Meister, Björn
AU - Berggren, Per Olof
AU - Bark, Christina
PY - 2005/4/8
Y1 - 2005/4/8
N2 - Insulin secretion from pancreatic β-cells has to be tightly regulated to ensure accurate glucose homeostasis. The capacity of β-cells to respond to extracellular stimulation is determined by several signaling pathways. One important feature of these pathways is phosphorylation and subsequent dephosphorylation of a wide range of cellular substrates. Protein phosphatase 1 (PP1) is a major eukaryotic serine/threonine protein phosphatase that controls a multitude of physiological processes. We have investigated the expression and cellular distribution of two endogenous inhibitors of PP1 activity in β-cells. RT-PCR, Western blotting, and immunohistochemistry showed that DARPP-32 and inhibitor-1 are present in insulin-secreting endocrine β-cells. Subcellular fractionation of mouse islets revealed that both PP1 inhibitors predominantly localized to cytosol-enriched fractions. Inhibitor-1 was also present in fractions containing plasma membrane-associated proteins. These data indicate a potential role for DARPP-32 and inhibitor-1 in the regulation of PP1 activity in pancreatic β-cell stimulus-secretion coupling.
AB - Insulin secretion from pancreatic β-cells has to be tightly regulated to ensure accurate glucose homeostasis. The capacity of β-cells to respond to extracellular stimulation is determined by several signaling pathways. One important feature of these pathways is phosphorylation and subsequent dephosphorylation of a wide range of cellular substrates. Protein phosphatase 1 (PP1) is a major eukaryotic serine/threonine protein phosphatase that controls a multitude of physiological processes. We have investigated the expression and cellular distribution of two endogenous inhibitors of PP1 activity in β-cells. RT-PCR, Western blotting, and immunohistochemistry showed that DARPP-32 and inhibitor-1 are present in insulin-secreting endocrine β-cells. Subcellular fractionation of mouse islets revealed that both PP1 inhibitors predominantly localized to cytosol-enriched fractions. Inhibitor-1 was also present in fractions containing plasma membrane-associated proteins. These data indicate a potential role for DARPP-32 and inhibitor-1 in the regulation of PP1 activity in pancreatic β-cell stimulus-secretion coupling.
KW - Dephosphorylation
KW - Exocytosis
KW - Immunohistochemistry
KW - Insulin
KW - Phosphatase
KW - PP1 inhibitor
KW - RT-PCR
KW - Secretion
KW - Subcellular fractionation
UR - http://www.scopus.com/inward/record.url?scp=14644390289&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=14644390289&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2005.02.017
DO - 10.1016/j.bbrc.2005.02.017
M3 - Article
C2 - 15737638
AN - SCOPUS:14644390289
VL - 329
SP - 673
EP - 677
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 2
ER -