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Regulation of Organelle Movement in Melanophores by Protein Kinase A (PKA), Protein Kinase C (PKC), and Protein Phosphatase 2A (PP2A)
| Content Provider | Scilit |
|---|---|
| Author | Reilein, Amy R. Tint, Irina S. Peunova, Natalia I. Enikolopov, Grigori Gelfand, Vladimir |
| Copyright Year | 1998 |
| Description | Journal: Journal of Cell Biology 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. α-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. |
| Related Links | http://jcb.rupress.org/content/142/3/803.full.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2148163/pdf http://jcb.rupress.org/content/jcb/142/3/803.full.pdf |
| ISSN | 00221295 |
| DOI | 10.1083/jcb.142.3.803 |
| Journal | Journal of Cell Biology |
| Issue Number | 3 |
| Volume Number | 142 |
| Language | English |
| Publisher | Rockefeller University Press |
| Publisher Date | 1998-08-10 |
| Access Restriction | Open |
| Subject Keyword | Journal: Journal of Cell Biology Plant Sciences Microtubules Protein Phosphorylation Microtubule Motors Kinesin Ii Cytoplasmic Dynein |
| Content Type | Text |
| Resource Type | Article |
| Subject | Physiology |