Regulation of organelle movement in melanophores by protein kinase A (PKA), protein kinase C (PKC), and protein phosphatase 2A (PP2A)

Reilein, A. R., Tint, I. S., Peunova, N. I., Enikolopov, G. N., Gelfand, V. I. (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

[img]
Preview
PDF
Enikolopov_JCellBiol1998.pdf

Download (1967Kb) | Preview
URL: http://www.ncbi.nlm.nih.gov/pubmed/9700167
DOI: 10.1083/jcb.142.3.803

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 Deposited: 01 May 2014 14:59
Last Modified: 01 May 2014 14:59
PMCID: PMC2148163
Related URLs:
URI: http://repository.cshl.edu/id/eprint/29925

Actions (login required)

Administrator's edit/view item Administrator's edit/view item
CSHL HomeAbout CSHLResearchEducationNews & FeaturesCampus & Public EventsCareersGiving