Reilein, A. R., Tint, I. S., Peunova, N. I., Enikolopov, G. N., Gelfand, V. I.
(August 1998)
Regulation of organelle movement in melanophores by protein kinase A (PKA), protein kinase C (PKC), and protein phosphatase 2A (PP2A).
Journal of Cell Biology, 142 (3).
pp. 803-13.
ISSN 0021-9525
Abstract
We used melanophores, cells specialized for regulated organelle transport, to study signaling pathways involved in the regulation of transport. We transfected immortalized Xenopus melanophores with plasmids encoding epitope-tagged inhibitors of protein phosphatases and protein kinases or control plasmids encoding inactive analogues of these inhibitors. Expression of a recombinant inhibitor of protein kinase A (PKA) results in spontaneous pigment aggregation. alpha-Melanocyte-stimulating hormone (MSH), a stimulus which increases intracellular cAMP, cannot disperse pigment in these cells. However, melanosomes in these cells can be partially dispersed by PMA, an activator of protein kinase C (PKC). When a recombinant inhibitor of PKC is expressed in melanophores, PMA-induced pigment dispersion is inhibited, but not dispersion induced by MSH. We conclude that PKA and PKC activate two different pathways for melanosome dispersion. When melanophores express the small t antigen of SV-40 virus, a specific inhibitor of protein phosphatase 2A (PP2A), aggregation is completely prevented. Conversely, overexpression of PP2A inhibits pigment dispersion by MSH. Inhibitors of protein phosphatase 1 and protein phosphatase 2B (PP2B) do not affect pigment movement. Therefore, melanosome aggregation is mediated by PP2A.
| Item Type: |
Paper
|
| Additional Information: |
0021-9525 (Print)
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S. |
| Uncontrolled Keywords: |
3T3 Cells
Animals
Cell Aggregation
Cell Line
Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors/*physiology
Enzyme Inhibitors/pharmacology
Melanocytes/metabolism/physiology
Melanophores/*physiology
Mice
Microtubules/physiology
Organelles/*physiology
Phosphoprotein Phosphatases/antagonists & inhibitors/*physiology
Phosphorylation
Pigments, Biological/physiology
Protein Kinase C/antagonists & inhibitors/*physiology
Protein Phosphatase 1
Protein Phosphatase 2
Transfection
Xenopus |
| Subjects: |
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > cell line
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > cell line
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > cell line
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > transcription factor > Cyclic AMP
organs, tissues, organelles, cell types and functions > organelles, types and functions
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein expression > phosphorylation
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > kinase > Protein kinase C
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein phosphatase
Investigative techniques and equipment > transfection
organism description > animal > Frog > xenopus |
| CSHL Authors: |
|
| Communities: |
CSHL labs > Enikopolov lab |
| Depositing User: |
Kathleen Darby
|
| Date: |
10 August 1998 |
| Date Deposited: |
01 May 2014 14:59 |
| Last Modified: |
01 May 2014 14:59 |
| PMCID: |
PMC2148163 |
| Related URLs: |
|
| URI: |
https://repository.cshl.edu/id/eprint/29925 |
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